- 2 tbsp. chopped fresh flat-leaf parsley
- 1 1/2 tbsp. chopped fresh rosemary
- 1 large garlic clove, chopped
- 2 tsp. Dijon mustard
- 3 tbsp. extra-virgin olive oil, divided
- Kosher salt
- Freshly ground black pepper
- 1 lemon, cut into thin slices, divided
- 4 small bone-in, skin-on chicken breasts (about 2 1/2 lbs. total)
- 2 bunches Broccolini (about 1 lb.)
- 1 red onion, cut into 1/2″ wedges
- 1/2 tsp. crushed red pepper, plus more for serving
- Preheat oven to 425 degrees F.
- Combine parsley, rosemary, garlic, Dijon, and 1 tablespoon oil in a bowl. Season with salt and black pepper. Place 8 lemon slices and half of rosemary mixture underneath skin of chicken, dividing evenly. Rub remaining rosemary mixture over chicken, dividing evenly. Roast, on a rimmed baking sheet, 20 to 22 minutes.
- Meanwhile, toss Broccolini, onion, red pepper, remaining lemon slices, and remaining 2 tablespoons oil in a bowl. Season with salt and black pepper. Remove baking sheet from oven and arrange vegetables around chicken. Bake until an instant-read thermometer inserted in the thickest portion of the chicken reaches 165 degrees F, 12 to 14 minutes.
- Serve with red pepper for sprinklings