- 1 3 1/2-4-pound chicken, backbone removed
- 1 tablespoon kosher salt plus more
- 1/2 teaspoon freshly ground black pepper plus more for seasoning
- 1/4 teaspoon cayenne pepper
- 4 tablespoons olive oil, divided
- 2 tablespoons finely grated lemon zest
- 3 tablespoons fresh rosemary leaves
- 1 large fresh poblano chile, quartered, seeded
- 1 large red bell pepper, quartered, seeded
- 1 red onion, cut into 1/2″ slices
- 1/4 cup (or more) red wine vinegar
- 2 garlic cloves, sliced
- 1 cup fresh basil leaves
- 4 avocados, halved and pitted
- 1/4 teaspoon chili powder
- Ingredient info: Poblano chiles are available at Latin markets, specialty foods stores, and some supermarkets.
- Special equipment: One brick, wrapped in foil, or a cast-iron skillet
- Open chicken and place on a work surface, skin side up. Using your palms, firmly press on breastbone to flatten the breast. Season chicken all over with 1 tablespoon salt, 1/2 teaspoon black pepper, and cayenne. Place in a baking dish; rub with 1 tablespoon oil, sprinkle with lemon zest, and scatter rosemary over. Let stand at room temperature for 1 hour.
- Build a medium-low fire in a charcoal grill, or heat a gas grill to medium. Place chicken, skin side down, on grill and place a brick or heavy skillet on top of chicken to weigh it down. (This will expose more skin to direct heat, making it crispy; the chicken will also cook faster.) Cook until skin is crispy and golden brown, about 15 minutes.
- Using tongs, set brick aside. Turn chicken, cover grill, and cook for 10 more minutes. Continue cooking and turning chicken every 10 minutes, covering grill between turns, until an instant-read thermometer inserted into the thickest part of the thigh registers 165°F, about 50 minutes total. Transfer to a carving board; let chicken rest for 10-20 minutes. (Resting will make for juicier meat.)
- While chicken rests, add more coals to fire if necessary to increase heat to medium, or heat gas grill to medium-high. Season chile, bell pepper, and onion with salt and pepper. Grill (or use a grill basket) over medium heat, turning occasionally, until softened and charred in spots, about 12 minutes. Transfer onion to a medium bowl. Transfer chiles and peppers to a work surface and cut lengthwise into 1″ slices. Add to bowl with onion. Add 1/4 cup vinegar to vegetables and toss to coat.
- Heat 2 tablespoons oil in a small skillet over medium-low heat. Add garlic and cook until soft but not browned, about 4 minutes. Add basil and stir to wilt. Add basil mixture to bowl with onion. Season vegetables to taste with salt and more vinegar, if desired.
- Rub cut side of avocados with remaining 1 tablespoon oil, season with salt, and sprinkle with chili powder. Grill, cut side down, until avocado is gently warmed and flesh is golden brown, about 3 minutes. Serve chicken with vegetables and avocados.