Prepare the cauliflower rice by pulsing cauliflower florets in a food processor until they resemble rice grains. Heat olive oil in a pan over medium heat, add cauliflower rice, and sauté for 5 minutes until tender.
In a large skillet, heat olive oil over medium heat. Add ground beef or turkey and cook for 5-7 minutes until browned. Drain excess fat if necessary.
Add chili powder, cumin, garlic powder, onion powder, salt, and pepper to the meat. Stir and cook for another 2-3 minutes to infuse flavors.
Add diced bell peppers and tomatoes to the skillet. Cook for 3-4 minutes until softened.
Assemble the bowl by layering cauliflower rice, seasoned meat, sautéed vegetables, shredded lettuce, cheese, sour cream, and salsa. Garnish with avocado and cilantro if desired.