Leftover Turkey Shepherd's Pie

Ingredients

• Approximately 1 lb. leftover roast turkey meat, chopped or shredded
• 1 small red onion, chopped
• 2 stalks celery, chopped fine
• 1 carrot, chopped fine
• 4 cups leftover turkey gravy (or turkey or chicken gravy from wherever you can get it)
• Butter, for sauteing and finishing
• 4 cups mashed potatoes
• Salt and pepper to taste