Add peppers, onions, and garlic to a food processor and pulse until well blended. If you have a smaller food processor you may want to do this in two separate sections so as not to overcrowd the container.
In a large sauté pan, heat olive oil over medium-high heat and then add the pepper, onion, and garlic mixture. Stir, and cook for about one minute.
Add all of the remaining ingredients to the pan and bring to a low rolling boil, stirring continuously.
Lower heat to low-medium, and allow to simmer for about 20 minutes. Be sure to stir the ingredients every few minutes during this time.
Notes
Makes: approximately 3 cups, depending on how thick you make the sauce. Can fill one 12-ounce glass jar/bottle or four mini mason jars.Substitutions: can substitute cornstarch if you do not have arrowroot powder.Consistency: The sauce should be slightly thick (thanks to the arrowroot powder), but not so thick that it's challenging to dip an egg roll into. It also should not be too runny or liquid, like water. Be sure to simmer it until it gets slightly thickened; you can also add more arrowroot powder or cornstarch in ¼ teaspoon amounts at a time until you get the desired consistency.Storage: store sauce in an airtight container in the refrigerator for up to one week.