It strikes me that this recipe isn't that different than the chili I posted previously, except blended and without the meat. Oh well, I'm pretty boring that way. This is just so tasty--and spicy, depending on how much heat you want to add--and so simple that I can't help but post it. It's also excellent reheated. Originally from Best Ever Soups (which I should probably get), but I saw it via http://www.macheesmo.com/2010/02/kidney-bean-soup/.
2 onions, diced
2+ cloves garlic, minced
1 jalapeno, diced (optional)
1 tablespoon cumin
1/4 teaspoon (or more) cayenne
1 tablespoon paprika
1/2 teaspoon dried oregano
1 tablespoon tomato paste
1 14-oz. can diced tomatoes
2 14-oz. cans kidney beans, drained
4 cups chicken or vegetable stock
salt & pepper to taste
lemon juice or vinegar to taste
Saute the onions in a soup pot with the olive oil until soft, 8-10 minutes over medium heat. Add garlic and jalapeno and cook for another minute. Stir in spices and roast for a minute or so then add tomato paste. When this is combined, add all the other ingredients except the lemon juice or vingar. Bring to a boil, then lower heat and simmer for 30 minutes. Cool slightly and blend (it's handy to have an immersion blender here, but you could use a regular blender as well.) Add a dash of lemon juice or vinegar (or some sort of acid) just before serving.
The original recipe also has a guacamole garnish, which is nice but not essential. Click on the Macheesmo site above if you want that recipe.