Preheat your oven to 425°F.
In a small bowl, combine olive oil, lemon juice, garlic powder, ground cumin, paprika, salt, and pepper to create the marinade.
Place the chicken breast in a shallow dish and coat it evenly with half of the marinade. Let it sit for at least 15 minutes.
Slice the red bell pepper, zucchini, and red onion into bite-sized pieces. Toss them in the remaining marinade.
Arrange the marinated vegetables on a baking sheet lined with parchment paper. Roast them in the preheated oven for 20-25 minutes until tender and lightly charred.
While the vegetables roast, grill or pan-sear the chicken breast for about 6-7 minutes on each side or until fully cooked.
Allow the chicken to rest for a few minutes before slicing it thinly.
Assemble the bowl by placing a bed of roasted vegetables and topping with sliced chicken, then garnish with additional lemon juice or fresh herbs if desired.