Cut the chicken breasts into bite-sized pieces. In a bowl, season the chicken with garlic powder, paprika, salt, and black pepper. Mix well so the chicken is evenly coated.
Heat the olive oil in a large skillet over medium-high heat.
Add the seasoned chicken to the skillet. Cook for 6–8 minutes, stirring occasionally, until the chicken is golden brown and fully cooked through.
Add the broccoli florets to the skillet and cook for 2–3 minutes until slightly tender.
Add the cauliflower rice and lemon juice. Stir everything together and cook for 2–3 minutes until the cauliflower rice is heated through.
Remove the skillet from the heat.
Divide the chicken, broccoli, and cauliflower rice mixture between serving bowls.
Top each bowl with sliced avocado, shredded cheese, and sour cream.