Heat a large skillet over medium heat. Melt butter in skillet; add rice and beans, stirring frequently. Cook until heated through, about 3 minutes. Add water, as needed, to get rice to desired texture. Remove from heat; set aside.

In a blender or mini food processor, combine 1/2 of an avocado, 2 tablespoons cilantro, and lime juice. Blend until sauce is thin. Add water if needed.

In 4 separate bowls, evenly divide rice and bean mixture, tomatoes, and corn. Sprinkle with salt and pepper. Drizzle with about 2 tablespoons of avocado-cilantro sauce. Top evenly with remaining avocado and cilantro. Add 1 tablespoon crushed tortilla chips to each bowl.