Cut tofu, zucchini, onion, green onion, and garlic into bite-sized pieces.
Heat cooking oil in a pot and stir-fry minced garlic and red pepper powder.
Add pork (optional) and stir-fry.
Add the chopped vegetables and water to the pot and bring to a boil.
Add soft tofu and let it simmer.
Season with salt and soy sauce.
Add egg and top with green onion, then bring to a boil once more to finish.