Shepherd's Meatloaf

1 lb lean chuck beef
2 Tbsp diced onion
1 tsp salt
1 cooked potato (medium), mashed
1 egg
1/2 tsp garlic powder
1/2 lb fresh mushrooms (sliced or 1 can drained)

In an 8-inch loaf pan, mix meat, onion, salt, potato, garlic powder and egg, thoroughly and form loaf. Firmly press mushroom slices over entire surface of loaf. Bake at 350 degrees for about 1 hour. Slice and serve.