Rinse chicken and cut away extra fat. Pat dry with paper towels inside and out. Place in shallow baking dish and rub softened butter all over chicken, tucking just a bit under the skin of breast.
Season generously with salt and pepper outside and inside cavity.
Stuff with garlic and lemon. Tie legs of the chicken together, slather sweet plum sauce all over chicken.
Set breast side down. Let sit 30 minutes at room temperature. Preheat oven to 450F. Roast chicken 20 minutes. Turn breast side up, lower temperature to 375F and return to oven. Continue to roast another 60-70 minutes, brushing with additional sweet plum sauce towards the end. You may have to loosely tent with tin foil if skin is approaching maximum crispiness (i.e. don’t burn the skin.)
Chicken is done when juices run clear as knife tip is inserted into chicken thigh. Thickest part of thigh without touching bone should register 170F. Let chicken rest 10 minutes before carving. Serve with a side of sweet plum sauce for dipping.Note: During roasting, cover with foil if chicken skin starts to burn, using the _____ technique as illustrated above with bits of foil and toothpicks.