Preheat Your Oven. Set your oven to 425°F. Line a large sheet pan with parchment paper for easy cleanup.
Prep the Ingredients. Slice the bell peppers, zucchini, red onion, and carrots into bite-sized pieces. Halve the baby potatoes (if using) for quicker cooking. If using chicken breasts, slice them in half lengthwise for even cooking.
Season the Ingredients. In a large mixing bowl, combine the chicken and vegetables. Drizzle with olive oil and sprinkle with garlic powder, paprika, Italian seasoning, salt, and pepper. Toss until everything is evenly coated.
Arrange on the Sheet Pan. Spread the chicken and vegetables in a single layer on the sheet pan, ensuring there’s space between the pieces for even roasting.
Roast to Perfection. Bake in the preheated oven for 25–30 minutes, flipping the chicken and tossing the vegetables halfway through. The chicken should reach an internal temperature of 165°F, and the veggies should be tender with caramelized edges.
Garnish and Serve. Remove from the oven and garnish with fresh parsley and a squeeze of lemon juice. Serve hot and enjoy!