Preheat the oven to 425°F.
In a small bowl, combine paprika, cumin, garlic powder, salt, and pepper. Rub the spice mix over the chicken breast.
Place the chicken on a baking sheet and roast for 18-20 minutes or until fully cooked and juices run clear.
Meanwhile, toss the bell pepper, zucchini, red onion, and cherry tomatoes in olive oil, salt, and pepper, then spread them on another baking sheet.
Roast the vegetables for 15 minutes until they are tender with slight crisp edges.
In a skillet over medium heat, warm the cauliflower rice until heated through; season lightly with salt and pepper and fold in the lemon juice.
Slice the roasted chicken and assemble the bowl with a base of cauliflower rice, topped with roasted vegetables and chicken slices.
Finish with an extra drizzle of lemon juice if desired and serve immediately.