Heat up 2 tbsp of oil in a wide deep pan.
Saute minced garlic, grated ginger and chopped jalapeño on medium heat until the raw smell is gone, making sure it does not burn.
Add chopped celery, cilantro stems and white part of scallions. Saute for 2-3 minutes on medium heat.
Add chopped onions to the pan and saute for 2-3 minutes on high flame.
Add chopped green peppers and saute for 2-3 minutes on high flame.
Add grated/chopped cabbage and saute for 2-3 minutes on high flame.
Add grated/chopped carrots and saute for 2-3 minutes on high flame.
Add chopped string beans and saute for 2-3 minutes on high flame.
Mix in dark soy sauce, red chili sauce, vinegar, black pepper and salt.
Add 32 oz of low sodium vegetable broth or 4 cups of water to the pan and bring it to boil.
While waiting for the soup to come to the boil, mix ½ cups of water with 3 tbsp of corn starch. Mix it very well making sure there are no lumps in it.
Add the corn starch slurry to the boiling soup slowly while stirring constantly.
Let the soup boil for a 2-3 minute after adding cornstarch slurry. This will thicken the soup very well and cook the cornstarch completely. Don't worry if you find the soup to be thicker than normal. Adding tofu, cilantro and scallion to it later on will make it little thinner!
Once the soup is boiled for a couple of minute, add pressed down and cubed soft tofu along with chopped cilantro and scallions. Mix it carefully, making sure the tofu does not break. Add a little more water if you find the soup too thick.
Take it off the stove. Serve it hot topped with optional crunchy noodles. Check my note below to see how to make crunchy noodles at home.