Bring 1 cup of water to a boil with ½ tsp. salt (optional). Stir in rice. Cover and cook over low heat until water is absorbed, about 45 minutes, or cook rice in a rice cooker.
Meanwhile, rinse and drain beans. Add desired spices. Cook over low heat in a saucepan, or in a microwavable dish in the microwave.
Cut avocado into slices or dice into small pieces. Serve rice with beans on top, and garnish with avocado pieces.
Notes
This dish can be topped with a variety of add-ons: Try hot sauce, salsa, sautéed greens, or a fried egg.