Preheat the oven to 425°F (220°C).
In a medium saucepan, combine the rinsed quinoa and water. Bring to a boil over high heat, then reduce heat to low, cover, and simmer for 15 minutes or until water is absorbed and quinoa is fluffy. Remove from heat and let stand covered for 5 minutes.
While the quinoa cooks, prepare the chicken. In a small bowl, mix smoked paprika, garlic powder, salt, and black pepper.
Rub the chicken breasts with 1 teaspoon olive oil and then evenly coat with the spice mixture.
Heat a grill pan or skillet over medium-high heat. Cook the chicken breasts for 6-7 minutes per side or until internal temperature reaches 165°F (74°C). Remove from heat and let rest for 5 minutes, then slice into strips.
On a large baking sheet, toss the red bell pepper, zucchini, yellow squash, and broccoli florets with 1 tablespoon olive oil, 1/2 teaspoon salt, and 1/4 teaspoon black pepper.
Spread the vegetables in a single layer and roast in the preheated oven for 20 minutes, stirring halfway through, until tender and slightly caramelized.
In a small bowl, whisk together the Greek yogurt, lemon juice, Dijon mustard, minced garlic, 1/4 teaspoon salt, and 1/8 teaspoon black pepper to make the dressing.
To assemble the meal prep bowls, divide the cooked quinoa evenly among four meal prep containers.
Top each with equal portions of sliced grilled chicken and roasted vegetables.
Drizzle each bowl with the Greek yogurt dressing and garnish with chopped fresh parsley.
Cover and refrigerate for up to 4 days. Reheat before serving if desired.