Season the chicken: In a bowl, stir together chili powder, cumin, smoked paprika, garlic powder, onion powder, oregano, salt, pepper, and cayenne.
Toss chicken with 1 tbsp oil, spice mix, and lime juice until well coated. Let it sit while you heat the pan.
Cook the cauliflower rice: Heat 1 tbsp oil or butter in a large skillet over medium heat. Add cauliflower rice, salt, and pepper.
Sauté 5–7 minutes until tender but not mushy. Stir in lime juice if using. Transfer to bowls or a serving dish and keep warm.
Sear the chicken: In the same skillet, add remaining 1 tbsp oil over medium-high heat.
Add chicken in a single layer. Cook 5–7 minutes, stirring once or twice, until browned and cooked through. Taste and adjust salt if needed.
Prep the fresh elements: While the chicken cooks, chop lettuce, tomatoes, onion, cilantro, and jalapeño.
Slice avocado and set out cheese, sour cream, and lime wedges.
Build the bowls: Start with a layer of cauliflower rice and lettuce. Top with hot chicken, then add tomatoes, onion, cilantro, jalapeño, avocado, and cheese. Finish with a dollop of sour cream, a squeeze of lime, and a splash of hot sauce or salsa.
Serve immediately: Enjoy while the chicken is warm and the veggies are crisp for the best texture.