How to Make It
Heat the oven to 425°. In a large roasting pan, toss the potatoes and garlic with 1 1/2 tablespoons of the oil and 1/2 teaspoon salt. Put the pan in the upper third of the oven and cook, stirring once, for 15 minutes.
Meanwhile, coat the chicken with 1 tablespoon of the oil; arrange the pieces, skin-side up, in a smaller roasting pan. Sprinkle the chicken with the lemon juice, 1/4 teaspoon salt, and 1/4 teaspoon pepper. Top each piece of chicken with a piece of the butter.
Stir the potatoes. Put the chicken in the oven with the potatoes and cook for 10 minutes. Add the asparagus, the remaining 1 tablespoon oil, and 1/8 teaspoon each salt and pepper to the potatoes. Stir and continue cooking until the chicken, potatoes, and asparagus are done, 10 to 15 minutes longer. Remove both pans from the oven. Toss the potatoes and asparagus with the lemon zest. Serve with the chicken breasts.