If dried pinto (or red) beans are used instead of canned ones, wash and soak them overnight; then cook them slowly until tender, about 2 hours.
Brown meat in hot lard in a Dutch oven or heavy saucepot; add broth; cover and cook gently until meat is about half done.
Add caraway seed (if used), salt, chili powder and garlic.
Continue cooking until meat is tender; add beans.
Meanwhile, heat several tablespoons lard in a skillet; add onion, tomatoes and peppers (if used); cover and let simmer until vegetables are soft.
Force through a sieve and thicken with cornstarch (mixed with cold water before adding).
Stir thickened sauce into meat and beans.
Blend well.
Cook over low heat until thoroughly heated.
Add more seasoning, if needed.