Optional Variation: Use 3 cups cooked butternut squash instead of the potatoes and carrots. I like to use oven roasted butternut squash by cutting a whole squash in half, scooping out the seeds. Then turn it cut side down on a parchment lined rimmed baking sheet. Place in a preheated 400 degree oven for 45 minutes or until soft. How long will depend on the size of the squash. Let cool and measure out 3 level cups of squash to use in place of the potatoes and carrots.