Finely chop chili peppers, garlic, and onion.
Heat cooking oil in a pan and sauté the garlic and onion.
Add chopped chili peppers and chili powder, then sauté.
Add soy sauce, sugar, and vinegar, then mix well.
Add water and salt, then bring to a boil.
When the sauce thickens, turn off the heat and let it cool.