Preheat the oven to 425°F (220°C).
In a medium saucepan, combine the rinsed quinoa and 2 cups of water. Bring to a boil over high heat, then reduce to low, cover, and simmer for 15 minutes or until the water is absorbed and quinoa is fluffy. Remove from heat and let it sit covered for 5 minutes, then fluff with a fork.
While the quinoa cooks, place the chopped red bell pepper, zucchini, and broccoli florets on a baking sheet. Drizzle with 1 tablespoon olive oil, sprinkle with 1/2 teaspoon salt and 1/4 teaspoon black pepper, and toss to coat evenly. Roast in the preheated oven for 20 minutes, stirring halfway through.
Meanwhile, prepare the chicken breasts by patting them dry. In a small bowl, mix paprika, garlic powder, 1/2 teaspoon salt, and 1/4 teaspoon black pepper. Rub the spice mixture evenly over both sides of the chicken breasts.
Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Add the chicken breasts and cook for 6-7 minutes per side or until the internal temperature reaches 165°F (74°C) and the chicken is cooked through. Remove from heat and let rest for 5 minutes, then slice into strips.
In a large bowl, combine the cooked quinoa, roasted vegetables, sliced chicken, cherry tomatoes, chopped parsley, and lemon juice. Toss gently to combine.
Divide the mixture evenly into 4 meal prep containers. Allow to cool before sealing and refrigerating.
Store in the refrigerator for up to 4 days. Reheat in the microwave before serving.