Roast Beef Hash

3 cups cubed cooked potatoes 1 teaspoon vegetable oil 2 cups cubed leftover roast beef 1 cup sliced cooked carrot (optional) 1 (10 ounce) can roast beef gravy[...]

cooking spray 1/2 cup chopped onion 1/2 cup chopped green bell pepper 2 garlic cloves , minced 2 cups shredded cooked lean beef 2 cups peeled and cubed cooked[...]