1 pound ground beef sirloin
1 can black beans (15 ounces), rinsed
1/2 cup leftover white or brown rice, cold
1 tablespoon grill seasoning
1 tablespoon ancho chili powder
1 1/2 teaspoons ground cumin (about 1/2 palmful)
1 1/2 teaspoons ground coriander (about 1/2 palmful)
1 tablespoon vegetable oil
1/2 small red onion, finely chopped
1 jalapeño pepper or serrano chili pepper, seeded and finely chopped
1 clove garlic, grated or finely chopped
Grated peel and juice of 1 lime
1/2 cup sour cream
4 crusty rolls, split
4 leaves red leaf lettuce
1 tomato, sliced
In a large bowl, combine the beef, beans, rice, grill seasoning, chili powder, cumin and coriander. Form into four patties. In a large skillet, heat the oil over medium-high heat. Add the patties and cook, turning once and lowering the heat slightly for the last few minutes, until browned, 12 minutes.
While the burgers cook, in a medium size bowl, mash together the avocado, onion, jalapeño pepper, garlic, lime peel and lime juice. Stir in the sour cream.
Layer each roll bottom with a lettuce leaf, a tomato slice, a beef patty, guacamole and a roll top.