THE ESSENTIAL NEW YORK TIMES COOKBOOK
1 1/3 cups ketjap manis (a sweet soy-based sauce, available in Asian grocery stores)
1/4 cup Chinese black vinegar
2 tablespoons dark soy sauce
2 tablespoons Asian fish sauce
Juice of one lime
One 2-pound piece fresh pork belly, with skin
2 bunches scallions
1/2 cup rice vinegar
1 1/2 cups mayonnaise
1 clove garlic, put through a press or minced
2 teaspoons sambal oelek (Indonesian Malaysian chile paste) or Sriracha (Thai chile sauce)
24 thick slices white bread
24 large cilantro sprigs
Combine the ketjap manis, black vinegar, soy sauce, fish sauce, and lime juice in a bowl. Place the pork belly in a heavy 1 gallon freezer bag with a zip closure, pour in the soy sauce mixture, and seal the bag.
Place it in another freezer bag or bowl in case of leaks, and refrigerate for at least 24 hours (and up to 48 hours), turning from time to time.
The next day, heat the oven to 225 degrees.
Place the pork skin side up in a roasting pan with a close fit, pour in the marinade, and add about 1/3 cup water (more if needed), so the liquid comes halfway up the sides of the pork. Cover with a sheet of parchment, then cover tightly with foil.
Roast for about 3 hours, until a skewer inserted in the pork meets little or no resistance. Allow to cool in the pan for about 30 minutes.
While the pork cooks, trim the scallions, discarding all but about an inch of green, and slice very thin on an angle. Place in a bowl, toss with a little salt, and pour the rice vinegar over.
Cover and allow to marinate for at least 2 hours.
Mix the mayonnaise with the garlic and sambal oelek in a small bowl; refrigerate.
When the pork has cooled, remove the skin. Cut the pork into 4-inch-long chunks and cut each into very thin slices. You should be able to get at least 36 slices.
Place the bread on a work surface and spread with the mayonnaise mixture. Drain the scallions and scatter them over half the bread slices. Top each of these with 3 slices of pork lined up side by side.
Place 2 cilantro sprigs on the pork, then cover with the remaining bread, mayonnaise side down. Trim the crusts from each sandwich. Leave the sandwiches whole or cut into thirds, between the slices of pork, and serve.