Chashu is the oleaginous, delectably tender pork slices served on top of a bowl of tonkotsu. Evolved from Chinese char siu, or “pork roast,” these slices of pork simply melt in the mouth and add substance to the soup. Chashu may be braised, cooked in the soup itself, dry roasted, or sous vide. Here, we will be braising our pork in a soy-based braising liquid. You will notice that the recipe for the braising liquid is nearly the same as the ajitsuke egg brine, and this is no coincidence. After cooking the chashu, this braising liquid makes the most sublime brine in which to marinate the eggs.
Ingredients
3-5 pounds pork belly or shoulder
1 cup water
½ cup mirin
½ cup soy sauce
1 tbsp brown sugar
¼ cup sake
3-4 garlic smashed garlic cloves
1 bunch scallions, sliced into 1 inch pieces
1-2” ginger, peeled and diced
Instructions
- If using a flat pork belly, roll meat perpendicular to the grain and tie into a roll.
- Combine water, mirin, soy, sugar, sake, garlic, scallions, and ginger in a bowl.
- Preheat oven to 250°F
- On the stovetop, heat a cast iron or Dutch oven that can also go in the oven at medium high temperature.
- Meanwhile, season the pork on all sides with salt and pepper.
- Sear it on all sides for 3-5 minutes until browned.
- Add soy mixture and cover.
- Place in oven and braise for 2-4 hours, turning the pork over every thirty minutes or so until the pork has reached an internal temperature of 200°F.
- Remove from the oven and cool. Refrigerate the pork in the braising liquid. It’s easier to thinly slice chilled meat.
- Reserve the braising liquid.
- When ready to put into the soup, cut the chashu into 1/4” slices, warm gently, and serve.