Step 1

Rinse 2 pounds thin-cut bone-in beef short ribs under cool running water, focusing around the bones. Place in a large bowl and add enough cold water to cover the ribs. Refrigerate for at least 1 hour or up to 3 hours. Meanwhile, prepare the marinade.

Step 2

Peel 1/2 medium yellow and coarsely chop. Cut the whites from 2 medium scallions into rough 2-inch pieces. Place the onion and scallion whites in a blender. Thinly slice the dark and light green parts of the scallions, place in a small bowl, and refrigerate (this is for garnish).

Step 3

Add 4 peeled garlic cloves, 1/2 (8-ounce) can crushed pineapple, 2 tablespoons water, and 1/2 teaspoon ground ginger to the blender. Blend until smooth and pourable. If the mixture is too thick, add a splash of water to make it pourable. Transfer 1 cup of the mixture to a large bowl and discard the remaining or save for another use. If the mixture doesn’t make 1 cup, add a little water to make it to a 1 cup.

Step 4

Add the remaining 1 cup water, 1 cup soy sauce, 1/3 cup mirin, 1/2 cup granulated sugar, 1 tablespoon toasted sesame oil, and 1/2 teaspoon black pepper to the pineapple mixture. Whisk until the sugar is dissolved. Refrigerate until ready to use.

Step 5

Take the short ribs out of the water and rinse them again under cold water. Shake off the excess water and place in a large zip top plastic bag or large baking dish. Pour in the marinade and toss to make sure all the short ribs are coated and submerged into the marinade. Seal the bag or cover the bowl and refrigerate for at least 12 hours and up to 24 hours.

Step 6

When ready to grill, heat a grill pan or a large cast iron skillet over medium-high heat. Remove the short ribs from the marinade, shake off any excess marinade, and place on a plate (discard the remaining marinade). Add enough short ribs to the pan to sit in a single layer without touching. Cook until well browned, cooked through, and charred around the edges, about 2 minutes per side. Transfer to a clean plate and repeat cooking the remaining short ribs.

Step 7

Let the short ribs rest for 2 to 3 minutes, then cut between each bone with kitchen shears. Garnish with the reserved scallion greens and 1 tablespoon toasted sesame seeds. Serve with steamed rice and an assortment of leafy vegetables, such as lettuce and perilla leaves.