First, cook the rice and beans in the same pan (easy!) and then add your favorite toppings to make it your way.
Use butter knife to cut avocado in half lengthwise around pit. With your hands, twist both halves in opposite directions to separate. Use soupspoon to remove pit. Scoop avocado from skin into food processor; discard pit and skin.
Add water, cilantro, lime juice, sour cream, and ¼ teaspoon salt to food processor and lock lid into place. Process mixture until completely smooth, about 1 minute. Stop food processor. Carefully remove food processor blade (ask an adult for help). Use rubber spatula to transfer avocado crema to small bowl.
Set colander in sink. Pour beans into colander and rinse with cold water. Shake colander to drain well. Pour rice into fine-mesh strainer and rinse with cold water until water is no longer cloudy. Shake strainer to drain well. Set aside.
In 12-inch nonstick skillet, heat 1 tablespoon oil over medium heat for 1 minute (oil should be hot but not smoking). Add corn to skillet and use rubber spatula to spread it in even layer. Cook, stirring occasionally, until corn is lightly browned, about 5 minutes. Turn off heat. Use spatula to transfer corn to medium bowl. Cover bowl with aluminum foil.
Add onion, cumin, ½ teaspoon salt, and remaining 1 tablespoon oil to skillet and return to medium heat. Cook, stirring occasionally, until onion has softened, about 5 minutes.
Carefully stir in beans, rice, and broth and bring to simmer. Cover, reduce heat to low, and cook for 10 minutes.