Preheat the oven to 450°F.
In a small saucepan set over medium-low heat, combine the butter and minced sage. Cook until the butter is melted.
Rinse the chicken, remove the giblets (if included) and trim off any excess fat. Thoroughly dry the chicken then place it in a skillet, nonstick sauté pan or roasting pan.
Brush the chicken all over, as well as inside the cavity, with the melted sage butter then season the chicken all over (including inside the cavity) generously with salt and pepper. Place the apple wedges and smashed garlic cloves inside the cavity then using kitchen twine, tie together the legs.
Roast the chicken for 1 hour, basting it every 15 minutes with the juices and excess melted butter than collect in the pan. (Tilt the pan to collect the juices and spoon them back atop the chicken.)
Remove the chicken from the oven once it has reached an internal temperature of 165°F and let it rest for 10 minutes on a cutting board before slicing and serving.