Paprika-Roasted Chicken, Potatoes, and Radishes With Salsa Verde

Place rack in middle of oven; preheat to 425 °F. Mix mayonnaise, pepper, paprika, 2 chopped garlic cloves, and 1 1/2 tsp. salt in a medium bowl. Pat inside and outside of chicken dry. From edge of cavity, loosen skin from breasts and thighs. Push all but 2 Tbsp. mayonnaise mixture under skin, then gently rub outside of skin to evenly distribute over breasts and legs. Tie together legs with kitchen twine. Transfer chicken to a rimmed baking sheet and roast 25 minutes. Meanwhile, toss potatoes and radishes in bowl with reserved mayonnaise mixture. Reduce oven temperature to 400 °F. Remove pan from oven, arrange potatoes and radishes in a single layer in pan, and continue to roast until potatoes and radishes are crisp-tender and chicken juices run clear when thigh is pierced with a fork and an instant-read thermometer inserted into the thickest part of the thigh registers 165 °F, 18 –20 minutes more. Meanwhile, pulse cilantro, parsley, oil, lemon zest, lemon juice, 1 1/2 cups radish tops, 1 Tbsp. water, and remaining 2 garlic cloves and 1/2 tsp. salt in a food processor until coarsely chopped. Transfer chicken to a cutting board; let rest 15 minutes. Carve, serve with potatoes and radishes, and top with salsa verde.