Beef Manhattan | Command Cooking

Ingredients

• 1 large onion, sliced
• 3 tablespoons butter, divided
• 2 cups roast beef, leftover and shredded
• 1 (12-ounce) jar brown gravy
• 2 medium potatoes, cut up
• milk or half-and-half, to taste
• salt, to taste
• pepper, to taste
• 2-4 slices white bread