(Adapted from Epicurious.com)
Ingredients:
For the chicken:
6 cloves garlic, finely chopped
2 Tbsp. ground cumin
2 Tbsp. olive oil
2 Tbsp. paprika
1 tsp. freshly ground black pepper
1 tsp. dried oregano
2 tsp. kosher salt, divided
2 lemons
1 4-4 ½ pound chicken
For the green sauce:
1 cup (packed) cilantro leaves with tender stems
4 jalapeño or serrano peppers (or a combination), coarsely chopped, with ribs
1 clove garlic, finely chopped
1 Tbsp. olive oil
2 ½ tsp. fresh lime juice
¼ tsp. kosher salt
¼ tsp. freshly ground black pepper
¼ cup mayonnaise
Preparation:
Roast the chicken:
Arrange rack in middle of oven; preheat to 400°F.
Zest and juice one lemon to yield 4 Tbsp. juice. Separately, juice half of the second lemon and set aside. Reserve other lemon half for another use.
Mix garlic, cumin, oil, paprika, pepper, oregano, 1 tsp. salt, finely grated zest and 4 Tbsp. juice in a medium bowl.
Place chicken, breast side down, on work surface. Spatchcock chicken by cutting along both sides of backbone with kitchen shears. Remove backbone and discard or save for stock. Turn chicken breast side up and splay open. Press down on breastbone with palms until you hear it crack and chicken is as flat as possible. Pat chicken dry with paper towels. Sprinkle chicken all over with reserved juice from the second lemon.
From both edges of cavity, loosen skin from breasts and thighs, being careful not to tear skin. Using your fingers, gently spread 2 heaping Tbsp. spice mixture under skin (reserve remaining spice mixture), then season chicken all over with remaining 1tsp. salt. Transfer chicken, spread flat and skin side up, to a roasting pan or large skillet.
Roast chicken 20 minutes, then brush with spice mixture and any juices that may have accumulated in the pan. Continue roasting, basting with spice mixture and pan juices every 20 minutes, until an instant-read thermometer inserted into the thickest part of thigh registers 165°F, 50-60 minutes total.
Transfer chicken to a cutting board and let rest 15 minutes.
Make the green sauce:
Purée cilantro, jalapeños (or whatever peppers you’re using), garlic, oil, lime juice and salt in a food processor or blender until combined. Add mayonnaise and purée until well blended. Transfer to a small bowl, cover, and chill until ready to use.