Creating Sumac Chicken with Roasted Vegetables is straightforward when you follow these steps:

1. Preheat your oven to 425°F (220°C).
2. In a mixing bowl, combine ground sumac, paprika, garlic powder, olive oil, salt, and black pepper.
3. Add the chicken thighs to the bowl, tossing them to coat evenly with the spice mixture.
4. On a large sheet pan, arrange the seasoned chicken.
5. In a separate bowl, mix the broccoli, red bell pepper, zucchini, and red onion with a drizzle of olive oil, salt, and pepper.
6. Spread the vegetables around the chicken on the sheet pan.
7. Place lemon slices on top of the chicken and scatter any remaining over the vegetables.
8. Roast in the preheated oven for 25-30 minutes or until the chicken reaches an internal temperature of 165°F (74°C) and is golden brown.
9. Remove the pan from the oven and let it rest for a few minutes.
10. Garnish with fresh parsley if desired, then serve warm.

These simple steps will guide you in preparing this incredible sheet pan meal effortlessly, ensuring it’s both delicious and pleasing to the eye.