Remove tofu from packaging and drain from packing liquid. Wrap in paper towels, set over a wire rack or colander, and weigh down with a saucer or cup for about 15 to 20 minutes to extract moisture. Cut into 1-inch cubes.
In a pot over medium heat, combine pork belly, water, vinegar, bay leaf, 1 teaspoon of salt, and 1/4 teaspoon pepper.
Bring to boil uncovered and without stirring for about 3 to 5 minutes. Skim scum that floats on top.
Lower heat, cover, and cook for about 30 to 40 minutes until meat is tender. Add more water as needed in 1/2 cup increments to maintain about 1 cup of liquid. Drain meat, reserving liquid.
Meanwhile, in a pan over medium heat, add about 2 tablespoons of oil and swirl to fully coat the bottom of the pan. Heat until oil begins to shimmer but not smoking.
Add tofu in a single layer and cook until it begins to crisp, then turn to brown to other side. Remove from pan and drain on paper towels.
Alternatively, in deep, wide pan, heat about 2-inches deep of oil until very hot but not smoking. Add tofu in batches and cook, turning as needed, until golden and crisp. With a slotted spoon, remove from pan and drain on paper towels. Set aside.
In a skillet over medium heat, heat about 1 tablespoon of oil. Add onions and garlic and cook until softened.
Add pork and cook, stirring regularly, until lightly browned.
Add tomatoes and cook, mashing with the back of a spoon, until softened and release juices.
Add reserved liquid and bring to a boil.
Add tausi. Season with salt and pepper to taste.
Add fried tofu and briefly toss until just coated with sauce. Serve hot.
Wait until tofu begins to brown before turning or they will stick to pan and fall apart.