Cut bell pepper into halves and remove seeds and membrane. Roast on gas flame or under HIGH broiler until blistered. Cover charred bell pepper under a tea towel until slightly cooled. Scrape most of the charred pepper skin off with a paring knife. Quarter the pepper and place in food processor.
Add remaining ingredients to the bell pepper in the food processor. Pulse until smooth. Season with additional salt or vinegar, to desired taste.