Preheat and Prep: Heat oven to 425°F (220°C). Line a large rimmed sheet pan with parchment for easier cleanup.
Cut Evenly: Chop broccoli into florets, slice the pepper into strips, cut zucchini into half-moons, slice onion into wedges, and halve the baby potatoes.
Aim for similar sizes so they cook evenly.
Mix the Seasoning: In a small bowl, combine olive oil, lemon zest, smoked paprika, garlic powder, onion powder, oregano, chili flakes (if using), salt, and pepper.
Season the Chicken: Pat chicken dry. Toss with about one-third of the oil mixture until well coated.
Toss the Veggies: In a separate bowl, toss all veggies with the remaining oil mixture. Add an extra pinch of salt if needed.
Load the Pan: Scatter veggies across the sheet pan in a single layer, leaving small spaces for airflow.
Nestle the chicken pieces on top or alongside.
Roast: Bake for 20 minutes. Flip the chicken and stir the veggies. Return to the oven for another 10–15 minutes, until the chicken hits 165°F (74°C) and potatoes are tender with crisp edges.
Finish Bright: Squeeze the lemon juice over everything.
Add chopped parsley or dill. Sprinkle a little Parmesan or crumbled feta if you like.
Serve: Plate as-is, or with rice, quinoa, or warm flatbread to catch the juices.