2 tablespoons vegetable oil
1  large onion, sliced
1  sweet red pepper, sliced
1  sweet green pepper, sliced
1  scallion, chopped
1/4 teaspoon garlic powder
1 teaspoon oregano
1 teaspoon cumin
 salt
 Freshly ground black pepper
2 cups cooked black beans
4 cups cooked white rice or  cooked brown rice

Heat oil in a large skillet. Sauté onion until soft. Add peppers and scallion, and sauté until lightly browned. Add spices and black beans and gently heat through. Serve over hot rice.