This Root Veggie Mash with Butternut Squash Recipe is one of my favorites, and I make it every year for the holidays. I make a huge batch of it, and freeze the leftovers.
In this case, we made this dish with one large parsnip, one medium butternut squash, one rutabaga (I have also used turnips), 2 yellow onions, and 3 carrots.
Next peel the parsnip, and slice it into ¼" pieces. If it is a large one such as this, you may want to halve it or quarter it length wise first before slicing. Add them to the pot with the others.
Once soft, drain the vegetables.
Put it all back in the pot, add a stick of butter, about 1 teaspoon of thyme, salt and pepper.
mash the butternut squash and all the root veggies together.