Cauliflower and Butternut Squash Gratin

On a very rainy evening a few weeks ago,  writer and Good Commons chef Matthew Wexler (check out his blog Roo de Loo here--isn't that such a great name for a food blog?) and I piled into a cab and headed downtown to the stunning and creepy Angel Orensanz Center.

We went there to represent Good Commons at Edible Escapes, a food and travel fair hosted by Edible Manhattan magazine.

Chef Matthew brought along his signature "Bad Day Brownies" and homemade buttermilk ice cream, which we served to the folks who came by out table. There were dozens of vendors participating in the event, but we heard from many that Matthew's brownies and ice cream were one of the best things available. In fact--we ended up running out before the event ended!

Since there were so many goodies on offer, we took turns manning the table to go check out the other treats. One of my favorites was a creamy cauliflower gratin served by the folks representing Organic Valley dairy. In fact, the gratin was so good, that I found myself craving it for days after.

Though I came home from the event with a copy of the Organic Valley recipe, I took a few  liberties. Specifically, I wanted to use the trick I'd learned while making my butternut squash mac and cheese of creating a creamy base out of vegetable puree instead of a roux.

I gave it a shot and was pleased to find that it worked beautifully!

Even my butternut squash-hating husband loved the results!

Cauliflower and Butternut Squash Gratin

Ingredients
1 3lb head cauliflower, cut into florets (cut stems into smaller pieces and include them, too)
1 1lb butternut squash, peeled and cut into cubes (about 3 cups)
Kosher salt
1/2 cup heavy cream
1 teaspoon ground mustard powder
1 teaspoon smoked Spanish paprika
1/4 teaspoon cayenne pepper (more if you'd like additional heat)
Freshly ground black pepper
1/2 pound extra-sharp cheddar cheese, grated (can also use gruyere, fontina, or other semi-soft cheese)
1/2 cup panko bread crumbs (or regular plain bread crumbs)
1/2 cup freshly grated parmesan cheese
2 tablespoons butter, melted

Directions
Preheat oven to 375 degrees.

Bring a large pot of salted water to boil and add the cauliflower and butternut squash. Let boil for about 6 minutes or until the squash and cauliflower are fork tender. Drain and divide the squash and cauliflower (you can also cook them separately, but this saves water).

Spread the cauliflower out on a baking sheet, pat dry, and place in the oven for 2-3 minutes, just to remove some of the excess moisture. Remove from oven and set aside.

Puree the cooked butternut squash in a blender or food processor, then add to a large pot over medium heat. Add the heavy cream, mustard powder, paprika, cayenne, and black pepper and stir to combine. Let simmer for a few minutes, then add the grated cheese and stir until fully melted.

Pour half the sauce in an 8x11" baking or gratin dish, and then add the cauliflower, spreading it out in an even layer. Top with the rest of the cheese sauce, making sure everything is covered.

Combine the panko, melted butter, and parmesan cheese, then spread over the baking dish. Bake for 20 minutes or until the top is golden (you can also pop under a broiler for a few minutes). If you prefer, you can bake this in individual ramekins or bowls.