Mix ⅓ cup of water & 4 tbsp of corn starch to make corn starch slurry. Mix it very well making sure there are no lumps in this mixture. Keep it aside.
Heat 3 tbsp of oil in a deep wide pan.
Saute grated ginger, minced garlic and chopped serrano peppers on medium heat for 2-3 minutes, or until the raw smell of garlic goes away. Making sure it does not get burn.
Saute finely chopped onions, green peppers, cabbage, carrots, white part of scallions on medium/high flame for 2-3 minutes, stirring frequently.
Once the veggies are sauted, add 5 cups of liquid (veg broth or water) to the pan. Mix it well and bring it to boil.
Add Ching's dark soy sauce, Ching's red chili sauce, rice vinegar and tomato ketchup along with salt and black pepper powder. Mix well and simmer for a minutes.
Stir the corn starch slurry you made earlier to make sure the corn starch has not sattled down at the bottom.
While the gravy with veggies is boiling, slowly add the corn starch mixture while stirring continually to prevent any lumps.
Bring the gravy to boil, the gravy should thicken up by couple of minutes of boiling.
Once boiling, add the Manchurian balls to the gravy and mix carefully making sure the balls do not break. Cook it for another couple of minutes.
Taste it and add anything that's needed (i.e salt, pepper, red chili sauce sauce, dark soy sauce, rice vinegar, tomato ketchup etc).
Garnish it with chopped cilantro and scallions. Serve it hot with side of plain white rice, brown rice, quinoa, cauliflower rice or fried rice!