Pat chicken dry with paper towels. In a small bowl, mix chili powder, cumin, garlic powder, and 1/2 teaspoon salt. Rub spice blend all over chicken, pressing it in so it sticks.

Heat olive oil in a large skillet over medium-high heat until shimmering. Add chicken in a single layer and cook undisturbed for 5-6 minutes until deeply golden on the bottom. Flip and cook 4-5 minutes more until cooked through (165F internal temp). Transfer to a cutting board and let rest 5 minutes, then chop into bite-sized pieces.

In the same skillet (no need to wipe it out), add cauliflower rice and remaining 1/4 teaspoon salt. Cook over medium heat, stirring occasionally, until tender and any moisture has evaporated, about 6-8 minutes. It should look dry and slightly toasted in spots. Remove from heat and stir in lime juice and cilantro.

Divide cauliflower rice among 4 bowls. Top each with chopped chicken, then add avocado, salsa, sour cream, and cheese in separate piles so everyone can mix as they like. Finish with extra cilantro if you want.