Step 1
In a large skillet over medium heat, heat 1 Tbsp. oil. Add onions and peppers; season with salt and pepper. Cook, stirring frequently, until onions are translucent and peppers are tender, 7 to 10 minutes. Transfer to a plate.
Step 2
In same skillet over medium-high heat, heat remaining 1 Tbsp. oil until very hot, about 30 seconds. Arrange steak in pan and pour lime juice over. Add chili powder and cumin; season with salt and pepper. Cook steak, undisturbed, until browned, 2 to 3 minutes. Continue to cook, stirring occasionally, to your preference, about 2 minutes more for medium. Transfer to another plate.
Step 3
Divide rice among bowls. Top with steak, onions, peppers, avocado, beans, and corn. Top with cilantro. Drizzle with sour cream.
