Heat the vegetable oil in a skillet over medium-high heat.

Add the ground beef to the skillet, breaking it apart with a spatula. Cook until browned, about 5-7 minutes.

Drain any excess grease from the skillet.

Return the skillet to heat and add the chopped onions. Sauté until softened, about 3-4 minutes, then add minced garlic and cook until fragrant, about 30 seconds.

Stir in the taco seasoning and water, bringing to a gentle simmer for 2-3 minutes.

Add black beans, corn, and diced tomatoes and simmer for an additional 3-5 minutes.

In a separate bowl, combine the cooked rice with cheddar and Monterey Jack cheese.

Warm the flour tortillas until pliable.

Lay a warm tortilla flat, spoon 1/2 cup of the beef filling in the center, and top with the rice and cheese mixture, sour cream, and cilantro.

Fold the sides and bottom of the tortilla over the filling and roll tightly.

Pan-fry the burritos seam-side down in a skillet with a little oil until golden brown and crispy, about 3-4 minutes.