In a hot saute pan heat oil and butter, add onion, garlic, red pepper flakes and chili powder, reduce heat to medium and cook until onions are golden brown. Add peanut butter, olive paste, brown sugar, molasses, soy sauce and water and cook, stirring occasionally, for approximately 8 minutes or until sauce is thick. Add lime juice and salt to taste. Remove from heat to a container with a cover and allow to come to room temperature before covering and refrigerating. Sauce will keep for up to 1 week.