If needed, cook brown rice according to its package; measure 2 cups after cooking. Drain and rinse the beans and prepare the corn as directed on its package.
Halve thick chicken breasts horizontally or pound to an even thickness of about 1/2 inch. Do not rinse raw chicken. Keep its board and utensils separate from the toppings.
Mix the olive oil, juice of 1 lime, chili powder, smoked paprika, cumin, garlic powder, onion powder, 1/2 teaspoon salt and black pepper. Coat the chicken. If preparing ahead, cover and refrigerate until cooking.
Heat a large nonstick skillet over medium heat. Add chicken in a single layer, working in batches if needed. Turn as it browns and cook until the thickest part of every piece reaches 165°F (74°C) on a food thermometer. Lower the heat if the spices begin to burn.
Move the cooked chicken to a clean board. Let it rest for 5 minutes, then slice. Discard any coating left in the raw-chicken bowl.
Stir the Greek yogurt with the juice of the second lime, a pinch of salt and 1 tablespoon chopped cilantro.
Divide the cooked rice, beans, corn and chicken among 4 bowls. Add tomatoes, avocado, red onion and 1/4 cup cilantro. Spoon the yogurt sauce over the bowls.
For meal prep, refrigerate in shallow containers within 2 hours, or 1 hour above 90°F (32°C). Keep at 40°F (4°C) or below and use within 3–4 days. Store cold toppings separately and reheat the cooked components to 165°F (74°C).