How to Make and Taste "New Onion Bombs": Hamburg Steaks Served in Spring Onion Cups

The dish uses new-season onions, and Ryuji used ones weighing about 300 g each. New onions are preferable, but Ryuji says regular onions work too.

First, cut off the top and bottom of the onion (in Ryuji's words, "the butt and the head"), split it in half down the middle, and peel it. Onions are made of layers from the outside in, so if you remove the inside while leaving about two outer layers, what remains forms a cup. The inside is easier to remove if you push from the back. This dish involves stuffing these cups with the meat mixture and cooking them. Ryuji showed off the finished cups, saying, "Cute, right?"

The removed insides aren't thrown away. There are two options: chop them and mix them into the hamburg steak, or turn them into a sauce. Here, Ryuji minced them all at once with a chopper (what Ryuji calls the "Bunbun Chopper"). If you don't have a chopper, you can chop them with a knife. Because the staff said "sauce would be good," the plan for the time being was to use all of it for the sauce.

Since this is a hamburg steak, 300 g of mixed ground beef and pork is used. Ryuji said the most important thing is the salt, adding half a teaspoon. Then come 9 shakes of umami seasoning, 6 shakes of pepper, and about 12 shakes of garlic powder. According to Ryuji, a little garlic powder makes it tastier.

Two handfuls of panko, about 20 g, go in. Ryuji explains that meat alone tends to get tough, but adding panko makes it fluffy and tender. No egg is used this time, in order to bring out the texture of the meat. Instead, 1 tablespoon of mayonnaise is added for fat, and once it's kneaded in well, the meat mixture is done.

When the staff remarked that the seasoning was "pretty simple," Ryuji replied that because the onions are delicious, it's better to keep the seasoning simple. If you want to get more elaborate, allspice or nutmeg would also be tasty, but since this recipe is about enjoying the aroma of new onions, this amount is just right.

The meat mixture was divided into four portions and stuffed into the onion cups. But once they were filled, it turned out there wasn't enough meat, and some ended up small. So Ryuji decided to mix part of the onion chopped for the sauce into the meat mixture to increase the volume. Another reason was that there was more chopped onion than needed for a sauce.

About 80 g was mixed in, roughly a third of the chopped onion. Ryuji said this makes the meat mixture tastier, adds volume, and lets you enjoy the crunch of the onion inside. When restuffed, every cup was packed full. Ryuji also said, "Whether you can make adjustments like this is what it comes down to when it comes to whether you can cook."

In the middle of the prep, the staff brought up the topic, saying, "You got into quite a few flame wars." Ryuji answered that if anything, it was the other side that was getting flamed. Ryuji had clashed with anti-fans, but says they never started anything themselves and only brushed off the sparks that came their way. Ryuji's view is that they were simply responding to what the other party said, and the other side came at them. The staff said they had seen how it unfolded. Ryuji laughed that their strong sense of justice is the problem, and said that this kind of stimulation is what makes being a YouTuber interesting, and that you don't normally get experiences like this.

Lightly coat a new frying pan with olive oil and cook the cups meat-side down. The lid goes on to soften the onions. According to Ryuji, onions that are still rawish aren't tasty. With the lid on, the onions steam, and the onion cups themselves become tender. The timing is "by feel"; the idea is that it's done when the onions are soft.

Once the meat has browned, flip them early and keep steaming. The steaming time is longer after flipping. At this point, the remaining chopped onion goes around the hamburg steaks. The staff said they had assumed it would be added at the end, but Ryuji gave two reasons. New onions are a little pungent when raw, so if they're going into a sauce, it's better to cook them. Heating them separately at the end takes time, and steaming them together lets the onion aroma transfer to the meat.

Ryuji initially explained that after flipping, you cover and steam for about 5 minutes, until they're soft enough to cut with a knife. In practice, though, when Ryuji poked a knife into an onion partway through to check, there was still some resistance. After steaming a few more minutes, Ryuji revised the estimate, saying, "It probably needs about 10 to 12 minutes of steaming." If the onion is hard, it has a crunchy bite, which isn't right either, so the guideline is to soften it until a fork slides right through. You can add water when steaming, but Ryuji's view is that if you don't need to add it, don't.

Ryuji said that this recipe is really more about eating onion than meat. They could have used two onions' worth for the cups and made it meat-focused, but since Ryuji hasn't been making many vegetable dishes lately, they want people to think of this as a recipe for eating lots of onion.

While it steamed, the conversation turned to the event Ryuji held in Kumamoto the day before. Ryuji held a "lunch event" for the first time. Tickets were 15,000 yen per person, and 200 people attended. Ryuji had wanted it to be a bit cheaper, but said the food served was worth the price, and that it's apparently quite cheap by lunch event standards.

Though it wasn't planned, on the way out Ryuji went around to every table and took photos with all 200 attendees who wanted one. There was no script, and apparently some hosts just leave. When the staff said, "Like an idol," Ryuji answered that they're grateful there are people who want to come see someone like them, who isn't an idol and only cooks, and that it warmed their heart.

The staff also said that while going around the tables, several attendees approached them saying "I'm a fan" and asked for a handshake. Having shown their face, they couldn't run away, and they thought it would look bad if they alone hung back, so they steeled themselves. Ryuji was pleased that the staff are starting to be recognized too.

As the steaming neared completion, juices began bubbling out of the meat. The surrounding onions were slightly scorched, but Ryuji called it "fine," since that makes them tastier too. To finish, cheese is placed on top and melted. When the staff said they didn't think the version seen on social media had cheese, Ryuji answered that since there's so much onion, a bit of cheesiness makes it tasty. Regular melting cheese is fine, but Ryuji likes cheddar, so cheddar was used. When the hamburg steaks were moved to a plate, juices poured out.

Soy sauce is added to the cooked, meltingly soft onion left in the frying pan to make the sauce. The amount is about 2½ tablespoons, though you can make it with half that. No need to reduce it. Normally you'd add mirin, but new onions are sweet, so it's left out. Ryuji explains that the onion alone brings out sweetness and umami, so this is enough. The sauce is poured over, onion is placed around the sides, plenty of black pepper is added to Ryuji's taste, and parsley is scattered on top to finish. Looking at it, the staff said, "What kind of dish is this, I wonder."

Ryuji took a big bite and said, "This is good," and "Onions really are tasty." The staff said, "I might love this recipe," and also commented that it's better with cheese. They had often seen the recipe without cheese, but feel it's better with it.

Since the staff said it would probably go well with rice, they heated up some rice (about 200 g), topped it with the hamburg steak and sauce, and ate it. Both rated it "it goes well" and "twice as tasty," saying the piping-hot rice paired well. Ryuji said the onion cup alone makes you want to keep eating rice, and also that the soy-sauce-only sauce is delicious. The staff suggested ponzu would probably go well too.

To change up the flavor, Ryuji added Tabasco's "Majisco." Ryuji said it becomes a salsa-like sauce, and that cheddar cheese and Majisco go really well together, adding, "Glad I did that."

Both were surprised at how quickly they got full. Ryuji explained that it's filling because it's like eating two whole onions. With this batch, three is just right for two people, and it could also be shared among three or four. Ryuji also rated it as good value for money, since the onion adds bulk. Ryuji also said that when serving it, you shouldn't make a lot of other side dishes. They decided to wrap up the leftovers and reheat them later.

As for kids, the conversation concluded that Majisco aside, the combination of onion and cheese would probably make kids happy. Ryuji thinks that because the onion is fully steamed and soft, even small children can eat it easily. When making it with regular onions, Ryuji added the caveat that it might be better to steam them a little longer than new onions. Finally, Ryuji wrapped up by saying it's a hearty recipe that brings out the umami of sweet new onions, so please give it a try.