Mystery Sauce on Sushi? Ryuji Tries the "Algerian Sauce" That Went Viral on X on Sushi, a Burger, and Kebab Rice

According to Ryuji, in the viral post a foreigner bought packaged sushi from a supermarket rather than a sushi restaurant and dipped it in a mystery sauce, in the spirit of "I'm going to eat it with my favorite sauce." Ryuji says that ordinarily, doing something like this would likely draw anger from people in other countries, along the lines of "sushi is meant to be eaten with soy sauce." Japanese reactions, however, were tolerant; if anything, the conversation turned to "tell us what that sauce tastes like and how to make it," and people in Japan kept trying it for themselves.

The sauce is apparently from Algeria. The post included a hastily written recipe, but the quantities were unclear; all that could be determined was that it uses mayonnaise as a base along with harissa, a chili paste. Ryuji thought, "As a cooking researcher, I can't not try this," and made his own version before filming, which turned out to be very tasty.

Hearing "mystery sauce," A-ko imagined a hot sauce like Tabasco (Majisco). Ryuji says no, explaining that it is a spicy sauce made mainly from mayonnaise—not a hot sauce as such, but "a sauce that's spicy but has umami." In terms of style, it's close to the sauce on McDonald's chicken, the kind of flavor people abroad seem to like.

Ryuji says the method is simple: just put all the ingredients in a bowl and mix. The proportions Ryuji gave are as follows:

• Mayonnaise, 60 g (about 5 tablespoons)
• Ketchup, 20 g (about 1½ tablespoons)
• Grated garlic
• Onion, 30 g (about 1/8 of an onion), finely chopped
• Salt, 1 pinch
• MSG seasoning, 2 shakes
• Ichimi chili powder, ½ teaspoon
• Cumin powder, ½ teaspoon
• Tabasco, 3–4 shakes (if you have it)

According to the original recipe information, garlic and onion—especially onion—are essential, and they can apparently be either sautéed or raw. The onion isn't made into a paste but finely chopped with a knife. A chopper would work too, but Ryuji's judgment is that using a chopper for such a small amount just means more washing up. He also cautions against adding too much.

The heat is normally provided by harissa, but since most homes don't have harissa, ichimi chili powder is used as a substitute. Half a teaspoon is pretty spicy, but because it's coated in mayonnaise, it ends up merely "pleasantly spicy," he says. Cumin is a spice used in curry; if you don't have it, curry powder will do, but in that case use a bit less. If you don't have Tabasco, just adding a little lemon juice is fine—its role is to add acidity. Ryuji suspects the original recipe probably doesn't include MSG seasoning, but says adding it gives a flavor that suits Japanese tastes.

Talking about the process, Ryuji said he's often asked, "Do you actually do any cooking research?", so he wanted to show himself doing research every once in a while. In fact, he spends his days off doing this kind of test cooking, and on this day too he had spent the whole afternoon making this sauce.

The sauce can be eaten freshly made, but Ryuji recommends letting it sit for 10–15 minutes if possible. While it rests, the onion softens and the flavors meld, and the sharpness of the raw onion disappears. If you want to use it right away, you can soak the onion in water first to remove its bite.

The show also had a batch prepared and rested in advance, and the same amount of Tabasco was added to it as well. A-ko pointed out that the rested batch looked smoother, and Ryuji replied that while the color is the same, it becomes smoother because the onion softens. The freshly made version keeps the crunch of the onion, but he says it's still delicious.

Tasting the sauce on its own, both rated it "delicious." A-ko said, "If it goes with sushi, it probably goes with anything," and on the heat, said she broke into a sweat for a moment, so spice lovers might find it irresistible. Ryuji added that the heat comes from the ichimi chili powder, not the onion. His view is that Japanese people are probably almost entirely unfamiliar with this kind of sauce.

The sushi they bought was salmon and negitoro. Ryuji says that, to his palate, the only things that would go with this sauce were those two and maybe shrimp. However, the supermarket didn't have shrimp sushi.

First they dipped salmon sushi in the sauce, and A-ko's reaction was, "It might actually work." The two felt it was close to a California roll or the kinds of items that come around on a conveyor-belt sushi line. Ryuji said it would be great as a nori roll with avocado or cucumber. A-ko agreed it might be tastier with vegetables, while noting that it wasn't bad on its own either.

Next they tried "torched mayonnaise salmon sushi," brushed with the sauce and seared with a torch. Ryuji said, "It wouldn't be out of place on a sushi restaurant's menu." A-ko said the torched version was "twice as good." They then coated negitoro in the sauce and torched it too, and A-ko said she liked this one better. In the end, their preferences split: Ryuji favored the torched salmon, and A-ko the torched negitoro. Ryuji's thinking is that since negitoro is so soft, it would be even better with added texture from something like cucumber or lettuce.

A-ko said she couldn't really make sense of the flavor with the first piece of salmon, but got used to it over the second and third bites. Ryuji called the foreigner who came up with this way of eating it "a genius." On the other hand, the two also agreed it probably wouldn't go with fish like sea bream.

Prompted by A-ko's comment that "it seems like it would go great with bread," Ryuji makes a hamburger with the remaining sauce. Instead of the Chojuku bread he usually uses, he went with Royal Bread, because he felt he'd been using Chojuku too much.

The patty is 100 g of mixed ground beef and pork, unseasoned and not kneaded much. Ryuji explains that not kneading it gives it a meatier texture that's more burger-like, closer to the coarse-ground meat of authentic American burgers. You just press it into shape, sprinkle with salt and pepper, and cook it.

As for tomato, A-ko dislikes it so much that she usually asks for it to be left out of her burgers. Still, Ryuji puts it in, saying, "Tomato definitely goes with this." He used Yoda Farm tomatoes that had arrived that day, slicing them thin and sprinkling them with seasoned salt. Even A-ko, who doesn't like raw tomatoes, was able to eat it, saying it wasn't mushy and the flesh was firm.

For cheese, instead of the kind he usually uses, he went with the melting type (for pizza), because you get a lot for a low price. On lettuce, Ryuji says it's less a vegetable than something like an herb, and whether it's included or not completely changes the flavor. McDonald's burgers, he says, taste quite a lot of lettuce too. The sauce is spread generously so it gets in between the vegetables, since the sauce is the star this time. Once the fillings were stacked, the burger was wrapped in paper and cut in half with a sharp knife to finish.

The finished "Algerian burger" got the biggest reaction of the day from both of them. A-ko called it "shockingly good," saying the spicy sauce and tomato go together so well that tomato should definitely be included. Ryuji went so far as to say, "I think it's better than any sauce anywhere."

Ryuji had initially expected it to taste like McDonald's, but on eating it, he revised that: surprisingly, it wasn't very McDonald's-like, but more in the direction of Freshness Burger. The sushi was tasty too, but his verdict was that it couldn't beat the bread. He also said that although he often makes copycat McDonald's sauces, this was the best sauce even counting those—"good enough to build a business on." As for the tomatoes, both said they'd like to buy just the tomatoes.

The final dish is kebab rice, which has been popping up a lot at kebab shops lately. Ryuji has a kebab rice bowl recipe he released previously, which uses yogurt. This time, though, since the Algerian sauce serves as the sauce, he made a simplified version where the chicken is just coated in spices and cooked. He says another reason is that many homes don't have yogurt on hand.

He uses 150 g of chicken breast. Since you can't shave meat off a rotating spit at home the way kebab shops do, he slices it fairly thin on the diagonal. Cutting it small is the key, he says, because if the pieces are too big the flavor won't take. He seasons it with a fairly generous amount of salt and pepper, adds about ½ teaspoon of chili powder and 5–6 shakes of garlic powder, and rubs it in. Chili powder is different from chili pepper, and Ryuji says cooking with chili powder gives it an American, foreign-style aroma. He cooks it in a light coating of olive oil, though regular oil is fine too. Finally, he sprinkles on a little salt and cooks it until browned.

The plating was done kebab-stall style. A generous heap of shredded cabbage goes on top of the rice. Cabbage is standard in kebab rice, and Ryuji's guess is that shops pile it on because it's cheaper than meat. The chicken goes on top, the sauce is poured over generously, and tomato is added if you like.

In between the cooking, Ryuji also reminisced about a trip to Marseille, France, 20 years ago, when the city was full of kebab shops. Kebabs are popular as fast food all over the world, and there are plenty in Japan too, he noted.

After tasting the kebab rice, A-ko said this was the best of the three dishes. Ryuji, eating it next, was also surprised—"Isn't this way too good?"—and said it could be sold. It's good even with chicken breast, there's no need for yogurt sauce, and he feels this sauce alone would be enough for kebabs. The two also joked that there are probably shops using this sauce without saying so.

Comparing it with his earlier kebab rice bowl recipe, Ryuji said "this one might be better," though he didn't seem sure. A-ko compared them, saying the earlier recipe is also very tasty, but this one is spicier. Ryuji summed it up: this one is spicy and rich, while the earlier one is more refreshing. He also wondered aloud whether people in Algeria eat it with rice like this, too.

On ways to use it, Ryuji noted that, judging from the original post, the common way to eat it seems to be as a dip for karaage or fried chicken, or with french fries. Basically, it seems like it would go with anything that goes well with mayonnaise-based sauces. Regarding sushi, the original post apparently said they had also tried it on white fish, but that white fish is better with soy sauce. Ryuji himself guesses that besides salmon, tuna, octopus, squid, and shrimp would work.

Ryuji reflected that he usually uses X thinking of it as "a place for nothing but pointless arguments," but this exchange between a foreigner and Japanese users was really nice. He said it was only because of social media that he came across this dish. He makes a point of jumping on whatever's trending, he said, and this time that led him to a wonderful sauce.

Finally, Ryuji added that this is an Algerian sauce recipe with his own interpretation, so people should feel free to change it, and if it's too spicy, they can cut back on the chili. As for storage, he figures that since it uses raw onion, it will probably only keep for 2–3 days in the refrigerator. Before the raw garlic and onion are added, it will keep for quite a long time, so he suggested that might be a good way to store it, and closed the video with that.