Garlic Potatoes

15 lbs red potatoes, unpeeled and quartered
2 1/2 lbs butter, room temperature
2 large onions, chopped and sauteed in butter
14 oz romano cheese, grated
3/4 c chopped garlic
3 T salt
2 T oregano
1 T white pepper
  1. Bring a large pot of salted water to a boil.
  2. Add potatoes and cook until tender but still firm, about 45 minutes; drain.
  3. Stir in butter, cheese, garlic, salt, sautéed onions, and oregano.
  4. Mash with a potato masher.