Mashed Potato Pizza

I took a stab at making a mash potato pizza.  I used Grover for the crust.  My toppings consisted of well mashed potatoes and cheese.  I used a bit of milk and some of the roasted garlic oil I had on hand to make the mashed potatoes and I used provolone for the cheese.  Overall, it was not a bad pie, but I don't know that I would make it again.  I seemed like it was missing something.