Mix all sauce ingredients in a saucepan; heat to boiling, reduce heat and simmer 10 minutes. Place a skim coat of sauce on the bottom of an 8”x 8” baking pan. Dip a tortilla in the remaining sauce, fill tortilla with beans, cheese, olives and onion and roll up. Place in baking dish. Repeat with remaining tortillas. Pour sauce and grated cheese over top. Bake at 350°F for 30 minutes.