Preparation Place chicken on a work surface and use kitchen shears to snip off wing tips (they get in the way of the breasts during cooking; save them for stock). Turn chicken breast side down and use shears to cut along both sides of the backbone to remove it (save for stock along with those wing tips). Open up chicken and use the tip of a knife to cut a shallow line along either side of the rectangular bone and strip of cartilage in the middle of breast. Turn chicken skin side up and press down on center of breast to flatten chicken—you should hear the breastbone crack. Season generously on both sides with salt and pepper and let sit at room temperature at least 20 minutes and up to 1 hour. Preheat oven to 350°F. Heat a dry large cast-iron skillet over medium. Pat chicken dry with paper towels and season all over again with a light sprinkling of salt. Add oil to skillet, then chicken, arranging skin side down. Cover the bottom of another smaller cast-iron skillet with foil and place over chicken to weigh it down. Cook, peeking under foil and lifting chicken a bit to check, until skin is deep golden brown and crisp all over, 15–18 minutes. Remove top skillet and turn chicken skin side up. Transfer skillet to oven and roast chicken just until cooked through (an instant-read thermometer inserted into the thickest part of breast should register 160°F), 15–20 minutes. Carefully remove skillet from oven and place chicken skin side up (to preserve that crispness) on a plate to rest. Set skillet over medium-low heat and add shallot and red pepper flakes. Cook, stirring often, until shallot is softened and golden, about 3 minutes. Add wine and lemon juice and swirl skillet to emulsify. Reduce heat to low and add butter; cook, swirling to combine, until melted. Pour in juices that have pooled under chicken on plate; mix in parsley. Return chicken to skillet to serve.
Preparation Place chicken on a work surface and use kitchen shears to snip off wing tips (they get in the way of the breasts during cooking; save them for stock). Turn chicken breast side down and use shears to cut along both sides of the backbone to remove it (save for stock along with those wing tips). Open up chicken and use the tip of a knife to cut a shallow line along either side of the rectangular bone and strip of cartilage in the middle of breast. Turn chicken skin side up and press down on center of breast to flatten chicken—you should hear the breastbone crack. Season generously on both sides with salt and pepper and let sit at room temperature at least 20 minutes and up to 1 hour. Preheat oven to 350°F. Heat a dry large cast-iron skillet over medium. Pat chicken dry with paper towels and season all over again with a light sprinkling of salt. Add oil to skillet, then chicken, arranging skin side down. Cover the bottom of another smaller cast-iron skillet with foil and place over chicken to weigh it down. Cook, peeking under foil and lifting chicken a bit to check, until skin is deep golden brown and crisp all over, 15–18 minutes. Remove top skillet and turn chicken skin side up. Transfer skillet to oven and roast chicken just until cooked through (an instant-read thermometer inserted into the thickest part of breast should register 160°F), 15–20 minutes. Carefully remove skillet from oven and place chicken skin side up (to preserve that crispness) on a plate to rest. Set skillet over medium-low heat and add shallot and red pepper flakes. Cook, stirring often, until shallot is softened and golden, about 3 minutes. Add wine and lemon juice and swirl skillet to emulsify. Reduce heat to low and add butter; cook, swirling to combine, until melted. Pour in juices that have pooled under chicken on plate; mix in parsley. Return chicken to skillet to serve.