Wow, this is a great low-carb variation on shepherd's pie! I'm not even low-carbing--I just had some cauliflower I needed to use up, but I will definitely make this again. The mashed cauliflower topping is great. I didn't have any sour cream so I subbed in French onion dip, and that kicked it up a notch. The only caveat is that it really only makes about 4 servings if you're serving it as a one-dish complete meal.