In a medium saucepan, combine water and vegetable oil and bring to a boil. Add both packages of rice. Cover and reduce heat to low. Simmer 7-10 minutes, until all water is absorbed. Remove from heat and allow to stand for at least 2 minutes.
In a medium skillet, combine ground beef, cumin, and salt. Cook over medium-high heat until beef is browned and cooked through. Drain well.
Add corn to a microwave-safe bowl and heat on HIGH power for 7 minutes until warmed through.
Place black beans in a microwave-safe bowl and heat on HIGH power for 1 minute until the beans are warm.
Serve this meal family-style where everyone can design their own Fiesta Rice Bowl with ingredients that they like.
Suggested order: rice, ground beef, black beans, corn, green bell pepper, red bell pepper, red onion, cheese. Stir to combine. Top with half of a sliced avocado.