Butternut Squash, Potato & Mushroom Gratin

I finished off my last box of farmer’s market tomatoes last week. It’s finally time to move on to root vegetables. I’ve been avoiding this moment, you see. Potatoes and butternut squash are available year-round in Wisconsin, while tomatoes are a seasonal, summery delicacy. Still, the times are a-changin'. This week it snowed and the temperatures dropped into the low 30s. The thermostat in my condo is stuck on 63. Winter’s here.

Slow-roasting is a great way to warm up the house (watch the thermostat jump past 68), and this recipe is a great way to cook potatoes and hard squash. This is based on Paula Wolfert’s potato and butternut squash pie, as featured and duly praised by the Wednesday Chef. Naturally, I tweaked the recipe.

Method:

Peel a medium butternut squash and 2 large potatoes. Slice into thin rounds (about 1/8 inch), and place in a large bowl. Preheat the oven to 350. Finely mince a couple of garlic cloves and a handful of parsley leaves. Add to bowl.

Mix in 4 oz. of some kind of cheese, shredded or diced. Wolfert’s recipe calls for an intricate mix of ricotta and hard sheep milk’s cheese, but, come on, nearly any kind of cheese will taste good with roasted butternut squash and potatoes. I’ve made this with ricotta and provolone, but I’ve also used havarti and blue cheese—trust me, it’s all good.

Mix the potatoes, squash and cheese mixture; season generously with kosher salt and black ground pepper.

In a skillet, sauté 8 oz. sliced mushrooms, preferably portabella, in olive oil. Season with salt; add a minced garlic clove during the last 30 seconds of cooking.

Spread out the squash/potato mixture in a foil-lined pan and top with mushrooms.

Pour a cup of milk over the vegetables. Bake at 350 for 40 minutes; then raise the temperature to 425 and bake 30 minutes. Broil for 5 minutes. Let cool a little before eating. This goes great with a pumpkin beer.