Fill a pot with water and set on the stove. Don’t turn it on just yet, though.

Peel and medium-dice your butternut squash. The smaller you dice it up, the quicker it will cook.

Peel and dice your onion (small to medium dices). Add both the squash and onion into the pot of water.

Cover the pot, but tilt the lid so steam is able to escape. Set on medium-high to boil. (Here’s a cool trick: if you’re in a rush, set that stove on high and watch it like a hawk so it doesn’t make a mess and bubble over—it should cook wicked quick. If you’re not in a rush and in fact don’t care how long it takes, you can set it on medium-low and do other things like wash dishes, make other food for the week, and so on.) You’ll know the squash is cooked when you can pierce it easily with a fork.

Carefully drain your squash and onions and leave them in the pot once drained. (Why make more dishes, right?)

Add in your butter, ghee, or coconut oil; rosemary; and salt and pepper. Mash the mixture. I use a fork to mash things up, but you can use a potato masher if you want to.

Taste test for seasoning, adjust if needed, and you’re all set!