1Mash half the beans with back of fork.
Saute onion in oil.
Add mashed beans, taco seasonings, and water.
Cook and stir 5 minutes or so to heat through completely.
Stir in 1/4 cup sour cream, and the whole beans. Cool.
2Spred mixture on a large platter.
Each layer that follows should be smaller than the one below it.
Top with layers of Guacamole (see recipe in my recipe box), salsa, and the remainingsour cream, and cheese.
Serve with tortilla chips.