Ryuji's Longtime "Sardine Tomato Pasta": From Hand-Filleting to a Slow-Simmered Sauce

The ingredients are sardines, 1.8mm pasta (two servings), zucchini, garlic, and a can of diced tomatoes. Ryuji explains that because the sauce is a sardine ragù (a slow-simmered sauce), slightly thicker noodles suit it better than thin ones. During the tasting, too, he said thin noodles would be overpowered by the umami of the sardines.

You can use other vegetables such as eggplant instead of zucchini, and since the dish is delicious without it, you can skip it if it's a hassle. It would also be tasty as an oil-based pasta, but this time he went with tomato sauce to make the most of how good simmered sardines are.

Ryuji estimates the sardines that day cost about 120 yen each. Sardines seem to be plentiful and cheap lately, but in Japan they're mostly grilled or simmered, and you don't often see people putting them in pasta. In Italy, on the other hand, they're commonly eaten with pasta, so he urged viewers to give it a try.

He uses a generous amount of garlic, about 20g. The reason is that sardines have a fishy, "green" smell, so the aroma of aromatic vegetables becomes important.

He slices about half the zucchini lengthwise into long, thin strips. He doesn't cut it into rounds partly because he's "tired of rounds," but he explained that long strips also cling to the pasta and are easier to twirl up with it.

Ryuji prefaced this by saying, "I'm not actually good at filleting fish," and said that's exactly why it's reassuring: "you can do it even if you're not good at it." The steps are roughly as follows.

1. Scale the fish (most of the scales had already come off that day) and cut off the head.
2. Cut the belly off at an angle and remove the innards and liver that come out.
3. Wash the inside of the belly thoroughly, scraping out the blood that collects especially at the base of the bones. Ryuji introduced the importance of removing the fishy smell with the saying, "Wash a sardine seven times and it becomes sea bream."
4. Insert your fingers between the flesh and the bone and open the fish by peeling the flesh away from the bone (hand-filleting). Sardine flesh is very soft, so you can open it by hand without using a knife as you would for three-piece filleting.
5. Cut away the belly bones with a knife and snip off the hard fins with scissors. Finally, pull out the backbone.

You can remove the small pin bones with tweezers, but sardine bones aren't hard, so if they don't bother you, it's fine to eat them as is. Since you'll be breaking the fish up in the sauce anyway, it's no problem if the flesh falls apart a bit. Ryuji says this method suits people who aren't confident with a knife, and recommends sardines for anyone trying to fillet fish for the first time. The opened fillets can also be used for fried sardines.

He filleted three sardines that day, yielding about 130g of flesh. Ryuji said it's best to have three or four, adding that the more you put in, the more umami you get. You can peel off the skin, but there's fat between the skin and the flesh, so he left it on this time. Because he wanted to demonstrate hand-filleting, he bought whole sardines rather than sashimi-grade ones.

For those who find filleting a hassle, he mentioned that butterflied sardines are also sold. Compared with the ones that day, though, he said the sardines he opened himself were fattier.

Sauté the garlic in 2 tablespoons of olive oil. He left out chili pepper this time for people who don't like spicy food, saying you can add it to taste. Since there's no heat, he says it's better to lightly brown the garlic to bring out its aroma.

Next, add the zucchini, then add the sardines whole, without cutting them, and sear them. Sprinkle a pinch of salt over the sardine flesh.

He explained the reason for searing before simmering later in the video. Searing first drives out moisture and gets rid of the fishy smell at the same time. Ryuji called this the Japanese culinary approach of "yaki" (searing/grilling), explaining that in Italian cooking the fish is sometimes added straight to the tomato sauce without searing, but this time he incorporated the Japanese method. He also said that because he has no mentor, he never "goes against his teachings," so he's free to experiment.

Once seared, add the canned diced tomatoes. He used half a can this time, since a full can would make too much. The simmering of a ragù, he says, is the fish's umami transferring into the tomatoes. If you want to add even more umami, add fish-based seasonings such as minced anchovies or fish sauce.

Since there are no onions, the acidity stands out, so he adds 1 teaspoon of sugar. Ryuji explained this as "the logic of sweetness and umami," saying the sardines provide the umami. As you add two pinches of salt and simmer, the zucchini develops a crisp texture. The sardine flesh is very delicate and breaks apart just from shaking the pan. How much you break it up is a matter of taste, but he says it's tastier broken up a little.

Ryuji said that if the umami is lacking, you can boost it with Ajinomoto, but he didn't add any that day. His view is that it's not something you put in everything, but something to use when needed. Because he used three large sardines this time, they produced plenty of flavor. As a guideline, he said that with two sardines, three or four shakes would bring out the umami.

While boiling the water, he also repeated that "if the ingredients are good, you don't need umami seasoning" and "it's strictly something you add for adjustment." He added the caveat that the umami of fish varies from fish to fish, so if it tastes lacking, it'll be better with some added.

If you reduce the sauce a bit more and simmer the sardines without breaking them up, it becomes "Zucchini and Sardines Simmered in Tomato," which he says is also delicious with bread. This time he made it into pasta.

On his attachment to this pasta, Ryuji talked about how he used to eat. Sardines were sold extremely cheaply as a supermarket bargain item, so when he couldn't afford meat, he ate nothing but sardines. Back then, he could also buy saury for around 100 yen at the neighborhood supermarket, but it's gotten much more expensive now. He also recalled that going to an izakaya cost 3,000 to 4,000 yen per person, which felt like a luxury, so he usually drank at home.

Add salt to the water at about 1%, roughly the saltiness of soup. Seasoning the pasta itself helps it come together with the sauce, but he added that you don't absolutely have to salt the water, and there are delicious pastas made without salt.

People often talk about pasta scorching on the rim of the pot, and Ryuji explains that the cause is heat that's too high. On high heat, the flames reach the outside of the pot and burn the pasta sticking out. If the water is boiling, there's no need for high heat, and if you match the flame to the pot, it won't scorch. That said, even as he explained this, he scorched it a little that day too, laughing that "it hardly affects the taste" and "these things happen."

He pulls the pasta at about 9 minutes, against the 11 minutes on the package. Finishing it slightly firm keeps it tasty longer. He recommended the spaghetti he used this time as pleasantly chewy and delicious, and mentioned that many stores carry it these days. Sprinkling oregano would also be tasty, but since the sardine flavor is strong this time, he said it's better not to add anything extra, and completed the flavor with just diced tomatoes, sugar, and salt.

He makes the sauce before boiling the noodles so he doesn't have to rush. Once you're used to it you can do both at once, but since he himself sometimes overcooks the pasta, he recommended making the sauce first as the beginner-friendly approach.

Leftover diced tomatoes won't go to waste if you put them in a container and freeze them. In the fridge, he says they'll keep for about a week.

Besides sardines, the dish is also delicious with other silver-skinned fish like horse mackerel, or with mackerel. Ryuji says that when he used to make it with horse mackerel, he paired it with rosemary.

That led to a story about rosemary growing in front of his apartment building. It's edible if washed, but it's outdoors and he doesn't know how sanitary it is. He and the staff discussed how you shouldn't take plants from someone else's property, but it's fine to pick them if they're growing on your own property. Rosemary is very hardy and keeps coming back once it takes root, so he says it's often found at houses with large gardens.

Add a ladleful of pasta water to the sauce and transfer the firm-cooked pasta with tongs. You could use a colander, but he used tongs because washing one is a hassle. He tastes at this point to settle the final seasoning, adding a pinch of salt that day. To finish, he drizzles over a fragrant olive oil (that day, a slightly pricey one from Kaldi).

Tasting it, Ryuji was surprised by how strong the sardine umami was, calling it "a dish from a course meal." He emphasized that he didn't rely on seasonings and that the umami comes from the sardines alone. He explained that in Italy, cheese isn't put on fish pasta because the fish provides umami, so he didn't add any here either.

To change up the flavor, he added "Majisco," a spicy condiment of his own making. He says you can make it without heat for kids and adults can add spice afterward. As for the small bones, he and the staff said they "weren't bothersome at all."

Finally, Ryuji looked back on how the dish works. Ragù means "to simmer," and the technique here is to break up the boneless sardine flesh and simmer it to release its umami into the sauce. Sardines are a fish with such strong umami that they're the raw material for anchovies, and he says they pair very well with pasta.

Ryuji said, "I'd forgotten how much I loved fish pasta" and "Why didn't I put out this pasta sooner?" He closed the video by saying that sardines are cheap right now, so now is the time to try it, and encouraged viewers to make it, whether with butterflied sardines from the store or ones hand-filleted like that day.