In a food processor, add in the chili peppers, onion and garlic. Process until desired consistency. I like mine a rough mince.
In a wok, large pot or large sauté pan, heat the cooking oil until shimmering on medium high heat. Add in the pepper/onion/garlic mixture and cook until fragrant, about 1 minute. Add in the remaining ingredients, mix well and bring to a simmer. Turn heat to low and cook for 20 minutes, stirring occasionally. Quickly taste and decide if you would like to add more spicy-hot chili pepper.
Taste and adjust seasonings. If you feel like it needs more saltiness and savoriness, add 1 tablespoon of fish sauce. Need it sweeter - 1 tablespoon brown sugar. If the sauce is lacking that tang, or high flavor note - 1 tablespoon vinegar.