2. Melt butter in a medium roasting pan over medium heat. Add apples, sprinkle with sugar, and cook, shaking pan occasionally, until apples are glazed and beginning to soften, about 8 minutes. Remove pan from heat and spoon some apples into grouse cavity, then put grouse, breast side up, into pan, pushing remaining apples to sides of pan. Brush grouse with buttery juices from pan.