Combine rinsed quinoa, chicken broth or water, and salt in a saucepan, bring to a boil, then reduce heat, cover, and simmer for 15 minutes.
Fluff cooked quinoa with a fork and set aside.
Preheat oven to 400°F (200°C).
Rub chicken breasts with olive oil, garlic powder, Italian seasoning, paprika, salt, and pepper.
Place chicken on a lined baking sheet and bake for 18-22 minutes until cooked through.
Rest chicken for 5 minutes, then slice.
Toss zucchini, bell pepper, broccoli, and onion with olive oil, salt, and pepper on another baking sheet.
Roast vegetables for 15-20 minutes, flipping once, until tender and caramelized.
Whisk together basil pesto, olive oil, and lemon juice until smooth and pourable.
Divide quinoa into bowls, top with roasted vegetables and sliced chicken.
Drizzle generously with pesto sauce and add optional toppings if desired.
Serve warm or use as chilled meal prep bowls.