Bean filling: Saute onions till transparent. Add some garlic and protein and cook for 5 minutes. Then add tomato juice, washed beans, taco seasoning, and cook till semi dry. Add some finely chopped red and green peppers and cook for another 5 minutes.
Pico de Gallo: Combine finely chopped tomato, onion, cucumber, serrano pepper, salt and lemon juice.
Guacamole: Deseed avocado and mix with chopped tomato, salt and lemon juice.
Fill shell and add extra toppings: cheese, sour cream, lettuce, tomato and salsa.