Heat the olive oil in a large saucepan over high heat. Add the onions, garlic, and bell peppers then saute for 10 minutes. Add the chicken stock and chili sauce. Bring to a boil before reducing heat to simmer, covered, until vegetables are very soft. Let cool then puree in a processor or blender. Makes about 3 1/2 cups. May be stored for brief periods if refrigerated. Substitute reduced amount of hot pepper sauce for Szechuan chili sauce. Serve with stir-fried or steamed chicken, fish.