Roast peppers in a 400 degree oven until blackened on all sides. Remove from oven to a plastic bag and allow to cool. Peel, seed and slice peppers, reserving juice. Place peppers with juice in a bowl and add cumin, red pepper flakes, garlic and salt to taste. Let stand for 1 hour, covered at room temperature or in the refrigerator for up to 8 hours. Allow to come to room temperature before serving. Serve with spicy sausages or barbecued meats.