Cook the tofu: Heat a large heavy-bottomed skillet or wok over high heat. Add 3 tablespoons oil. When the oil begins to smoke, remove the skillet from the heat and quickly (and carefully!) add the tofu in a single layer. Return the skillet to high heat and cook, stirring from time to time, until the tofu is lightly browned, 2 to 3 minutes. Carefully remove the tofu to a plate. Add the coriander seeds and toast for 15 seconds. Add the ground pork in a single layer, then sprinkle with salt and the red pepper flakes and brown over medium-high heat until cooked through, 3 to 5 minutes. Remove from the heat and add the pork to the tofu.
Cook the vegetables: Return the skillet to the heat and add the remaining tablespoon oil. Stir in the garlic and scallions and cook over medium heat for about 1 minute. Add the snow peas and peppers and cook until they become tender, 2 to 3 minutes. Stir in the soy sauce, honey, ginger and lemon zest and juice. Simmer for an additional minute. Taste for seasoning.
Finish: Add the pork and tofu back to the skillet and gently stir to reheat and combine, 1 to 2 minutes. Transfer to a platter and add the vinegar and additional soy sauce to taste.