A nutrient-rich spin on classic mashed potatoes, starts by using that transformational cooking technique known as, roasting. With a bit of oil, salt and pepper, and a hot oven, the once-intimidating butternut squash is transformed from an unappetizing brick to a soft and sweet base for a mashed side dish.
Place the butternut squash halves in a large, high-rimmed baking dish (I use an 11X17 baking dish). Drizzle 1 tablespoon of olive oil over the flesh of the squash. I also like to massage the drizzled oil on the flesh of the squash. Sprinkle the squash with just a couple of pinches of salt and pepper. Flip the squash over so the flesh is facing down.
Remove any extra papery layers from the outside of the garlic bulb. There should still be a papery layer keeping the individual cloves intact. Cut 1/4 inch off the top of the garlic bulb to expose the individual cloves nestled inside. Drizzle the remaining 1 TB of olive oil over the exposed garlic bulb, and then place the bulb, with the exposed cloves facing up, in between the butternut squash halves (or any other empty space in your baking dish). Cover the pan with foil and roast for 30 minutes, then remove the foil and continue to roast the squash and garlic until soft (about 15 more minutes, depending on the size of your squash). If the garlic clove is starting to burn, flip it over so the exposed cloves are facing down for the remaining 15 minutes. The end goal is a soft squash and soft garlic cloves.
While the butternut squash and garlic roast in the oven, place the peeled potatoes in a pot. Add just enough water to cover the potatoes. Bring to a boil, and then reduce to a lively simmer. Simmer the potatoes until soft, about 25 minutes. Drain the water from the soft potatoes.
Now it's time to mash the ingredients. Squeeze the individual garlic cloves away from the papery outside and into the pot of (drained) potatoes. Scoop the flesh of the roasted butternut squash away from the outside skin and into the pot. Add the olive oil and butter. I recommend waiting on the broth, since the final amount needed may vary depending on the size of your potatoes and squash.
Use a hand-mixer to cream the veggies, olive oil, and butter together. The squash and potatoes should be hot enough to melt the butter as you cream the ingredients together. Add the broth to the mashed veggies, adding as much as needed to reach your desired consistency. For me, this is 1/4 cup of broth. If you're using yukon gold potatoes, which tend to be creamier, you may not need 1/4 cup. Finally, stir in the salt and pepper to taste. The amount of salt added will depend on the saltiness of your broth and butter.