Step 1: Cook the Cilantro-Lime Rice
Rinse the rice under cold water until the water runs clear. In a medium saucepan, combine the rinsed rice, water or broth, butter, and salt. Bring to a boil, then reduce heat to low, cover, and simmer for 15-18 minutes, or until the liquid is absorbed and the rice is tender. Remove from heat and let it sit, covered, for 5 minutes. Fluff with a fork, then stir in the lime zest, lime juice, and chopped cilantro. Cover to keep warm.

Step 2: Season and Cook the Chicken
Pat the chicken dry with paper towels. In a small bowl, mix all the dried spices (chili powder, cumin, smoked paprika, garlic powder, onion powder, oregano, salt, and pepper). Drizzle the chicken with olive oil and lime juice, then rub the spice mixture evenly over all sides. Heat a large skillet or grill pan over medium-high heat. Cook the chicken for 6-8 minutes per side (for breasts) or 8-10 minutes per side (for thighs), until cooked through (internal temp of 165°F / 74°C). Transfer to a cutting board, tent with foil, and let rest for 5-10 minutes before slicing into strips or cubes.

Step 3: Whip Up the Creamy Fiesta Sauce
While the chicken cooks, prepare the sauce. In a medium bowl, whisk together the sour cream, mayonnaise, buttermilk (start with 2 tablespoons and add more to reach your desired drizzle consistency), lime juice, taco seasoning, and minced garlic until smooth. Stir in the chopped cilantro. Taste and adjust seasoning with salt and pepper. Cover and refrigerate until ready to use.

Step 4: Prepare All Toppings
This is your mise en place. Dice the tomatoes and avocado. Finely dice the red onion. Rinse and drain the black beans, then warm them gently in a small pot or the microwave. Prepare the corn (thaw if frozen, drain if canned). Shred the lettuce and cheese. Arrange all toppings in small bowls for easy assembly.

Step 5: Slice the Rested Chicken
After the chicken has rested, slice it against the grain into ½-inch thick strips or bite-sized cubes. This ensures maximum tenderness.

Step 6: Assemble Your Masterpiece Bowls
In individual serving bowls, start with a generous base of warm cilantro-lime rice. Arrange sliced chicken, warm black beans, and corn over the rice. Artfully add your chosen toppings: diced tomatoes, avocado, red onion, shredded lettuce, and cheese.

Step 7: The Grand Finale – Sauce and Serve
Drizzle the creamy fiesta sauce generously over the entire bowl. Add final optional garnishes like pickled jalapeños, crushed tortilla strips for crunch, and a fresh lime wedge on the side. Serve immediately, encouraging everyone to mix their bowl to combine all the glorious layers.