Tacos with Bean and Corn Filling
With a sharp knife, cut a shallow "X" on the bottom of each tomato. Blanch tomatoes for 1 minute in boiling water. Drain and rinse in cold water, then drain again. Peel tomatoes and cut into quarters, remove seeds and cut into pieces.
Peel onion and garlic and dice.
Heat oil in a pan. Sauté onion and garlic. Add tomatoes and simmer for 1-2 minutes. Drain beans and corn and add to pan with tomatoes. Stir in tomato paste and ketchup and simmer for 2-3 minutes. Season with salt, pepper and chili powder.
Rinse lettuce and spin dry. Cut lettuce into thin strips, if desired. To serve, fill taco shells with bean filling and lettuce.