-
Put oven rack in middle position and preheat oven to 450ºF.
-
Remove and discard fat from cavity of chicken and pat chicken very dry inside and out. Tuck wings under but do not truss chicken. Sprinkle chicken inside and out with salt and pepper and arrange, breast side up, on rack in roasting pan. Roast until thermometer inserted into fleshy part of thigh (do not touch bone) registers 170ºF, 50 to 55 minutes.
-
Meanwhile, stir together butter, mustard, and lemon juice in a small bowl until fluffy.
-
Transfer chicken to a cutting board and dab a teaspoon of mustard butter on hot chicken to cause skin to glisten.
-
Let chicken stand at room temperature 15 minutes.
-
Carve chicken and serve with remaining mustard butter on the side.