Cook the base. Prepare brown rice according to package directions, or warm pre-cooked rice.
For a lighter bowl, sauté cauliflower rice with a little olive oil and salt until tender, 4–5 minutes.
Warm the beans and corn. In a small saucepan, heat black beans and corn with a splash of water and a pinch of salt until warmed through. Keep on low.
Season the beef. In a bowl, mix the chili powder, cumin, smoked paprika, garlic powder, onion powder, oregano, cayenne (if using), salt, and pepper.
Brown the beef. Heat olive oil in a large skillet over medium-high. Add the ground beef, breaking it up.
Cook until just browned, 4–6 minutes. Drain excess fat if needed.
Add spices and simmer. Sprinkle the seasoning over the beef. Add 2–3 tablespoons of water and stir.
Let it simmer 1–2 minutes until fragrant and well coated. Taste and adjust salt or heat.
Prep fresh toppings. While the beef cooks, chop the lettuce, halve the tomatoes, dice the red onion, and cube the avocado. Chop cilantro and cut lime into wedges.
Make a quick sauce (optional). Stir Greek yogurt with a squeeze of lime, a pinch of salt, and a dash of hot sauce.
Thin with a teaspoon of water if you prefer it drizzle-able.
Assemble the bowls. Add a scoop of rice or cauliflower rice. Top with seasoned beef, black beans, corn, lettuce, tomatoes, red onion, and avocado.
Finish with extras. Sprinkle cheese and cilantro. Add a dollop of Greek yogurt or drizzle the sauce.
Squeeze fresh lime over the top for brightness.
Serve. Mix as you eat to get a little of everything in each bite. Add hot sauce if you like more heat.