You might like this recipe. After being given a description of the Root Smash from Cinderella's, this one probably comes close.
Root Mash
Harbor View Cafe, Pepin Wisconsin
3 lb. Yukon Gold potatoes
1/2 lb. parsnips
1/2 lb. turnips
1/2 lb. rutabagas
1 carrot
3/4 C. garlic, peeled
3/4 C. heavy cream *
Peel all the vegetables and cut them into small pieces. Boil the potatoes in one pot, the root vegetables in another.
Bring the cream and garlic to a boil, then simmer until garlic is soft.
Mash the cooked, drained potatoes. Drain the root vegetables (save some liquid if you need to adjust the mixture later) and blend them in a food processor. Slowly add the garlic mixture to the root vegetables and blend well.
Combine the mashed potatoes and root vegetables together. Add white pepper and salt to taste.
* For a lighter version substitute chicken broth for the heavy cream.
If you prefer, you could also substitute carmelized onions for the garlic. Slice 3/4 C. sweet onions and carmelize in a small pan over low heat with a bit of butter or oil. Heat the cream alone and add to the root vegetables as directed. After the potatoes and root vegetables are mixed, add the onions.