Heat the oven to 425°F (220°C).
Line a large sheet pan with parchment or lightly oil it so nothing sticks.
Prep the chicken. If the breasts are thick, butterfly or pound them to an even 1/2–3/4 inch thickness so they cook evenly. Pat dry with paper towels.
Season both sides with salt and pepper.
Set up a breading station. In one shallow bowl, mix the flour with a pinch of salt and pepper. In a second bowl, beat the eggs (add 1 teaspoon Dijon if you want extra tang).
In a third bowl, combine panko, Parmesan, garlic powder, onion powder, paprika, and Italian seasoning.
Bread the chicken. Dredge each piece in flour (shake off excess), dip in egg, then press into the Parmesan–panko mixture until fully coated. Set on the prepared pan.
Drizzle or mist the tops with olive oil for better browning.
Toss the broccoli. In a bowl, toss florets with 2 tablespoons olive oil, salt, pepper, and a pinch of red pepper flakes if you like. Spread on the same pan if there’s room, or use a second pan for best crisping.
Don’t overcrowd.
Bake for 12 minutes. Flip the chicken, give the broccoli a quick stir, and continue baking another 8–12 minutes, until the chicken is golden and the internal temperature reads 165°F (74°C). Broil for 1–2 minutes at the end if you want extra color.
Finish and serve.
Grate a little extra Parmesan over the broccoli, add a squeeze of lemon over everything, and sprinkle with chopped parsley if using. Serve hot.