Step 1 Soak the cascabel, guajillo and japones chiles in warm water until softened. Roast the bell peppers over a burner flame or under the broiler, turning them until evenly charred on all sides and soft, about 7 to 10 minutes. Cover them in plastic wrap until cool, then peel and seed. Remove the seeds from the chiles and tomatoes.
Step 2 Place the cascabel, guajillo and japones chiles, bell peppers, tomatoes and garlic in a food processor. Puree, adding olive oil as needed for a smooth texture, about 6 tablespoons. The result should be a thick paste. Add salt and pepper to taste.