I make something similar...

I cook up some cauliflower. When it's done i take my hand blender and puree until it looks like mashed potatos. I add my toppings (butter, sour cream, bacon, chives,no-salt, peper, garlic...anything goes...even cheddar cheese).
I make this 3-4 times a week. I haven't mised potatoes since I started!!

I will have to try your recipe. It's large enough for lots of left-overs!!

cin