Season the chicken: In a bowl, combine chili powder, cumin, smoked paprika, garlic powder, onion powder, salt, and pepper. Pat chicken dry, drizzle with olive oil and lime juice, and coat with the spice mix.
Cook the chicken: Heat a large skillet over medium-high. Sear chicken 5–6 minutes per side, until cooked through (internal temp 165°F/74°C).
Rest on a cutting board, then slice or dice.
Prep the base: Warm brown rice or quinoa. If using cauliflower rice, sauté with a little oil and a pinch of salt for 3–4 minutes until tender.
Sauté aromatics for queso: In a small saucepan, heat oil over medium. Add jalapeño and garlic; cook 1–2 minutes until fragrant but not browned.
Thicken the sauce: Whisk cornstarch into chicken broth until smooth.
Pour into the saucepan and bring to a gentle simmer, whisking until slightly thickened, 2–3 minutes.
Add cheeses: Lower heat to medium-low. Whisk in cream cheese until melted and smooth. Add shredded cheese in small handfuls, whisking until creamy.
Season with salt and a pinch of cumin or chili powder if you like.
Finish with yogurt: Remove from heat. Let cool 1 minute, then whisk in Greek yogurt until glossy. If too thick, whisk in a splash more broth.
If too thin, return to low heat and simmer briefly.
Warm mix-ins: In the chicken skillet, add black beans and corn with a splash of water. Warm over medium and scrape up any browned bits for extra flavor.
Assemble bowls: Add rice or cauliflower rice to bowls. Top with beans and corn, chicken, bell pepper, onion, tomatoes, and avocado.
Spoon warm queso over the top.
Finish and serve: Garnish with cilantro, lime wedges, and salsa if using. Taste and adjust salt, lime, and heat to your preference.