In a large soup kettle, sauté onions in a little water until they begin to soften.
Add the bell pepper and minced garlic and stir for 2 minutes.
Empty each can of beans, including its juice, the Rotel tomatoes, and the diced tomatoes.
Add the package of corn.
Mix well, add broth if you wish.
Cook over medium-low heat for 15-20 minutes until the soup is warmed thoroughly. Now, it is ready to serve!