For the dough: Combine the flour, cornmeal, salt and butter in a food processor and pulse until the butter forms pea-size or smaller pieces. Transfer the flour mixture to a stand mixer fitted with the paddle attachment. Whisk the water into the sour cream in a small bowl. With the mixer on low speed, slowly add the sour cream mixture and mix until a dough comes together. Divide the dough into 6 equal pieces and form into discs. Cover and refrigerate for at least 2 hours.
Preheat the oven to 425 degrees F. Line a baking sheet with parchment paper.
For the filling: Season the asparagus with salt and pepper and toss with 1 tablespoon of the olive oil. Roast on a baking sheet for 5 minutes and then set aside. Season the mushrooms with salt and pepper and toss with the remaining 2 tablespoons olive oil. Roast on a baking sheet for about 10 minutes. Let cook and then combine with the asparagus in a medium bowl. Reduce the oven temperature to 400 degrees F.
Blend the cream cheese with the 1/4 cup cream on low speed in a stand mixer fitted with the paddle attachment. Add the garlic, pepper flakes, lemon juice, cumin and thyme and blend until combined.
Whisk together the egg, 2 tablespoons heavy cream and a pinch of salt. Set the egg wash aside. Lightly dust a work surface and roll each of the chilled discs of dough into 6-inch rounds. Spread about 1/8 cup of the cream cheese mixture into a 3-inch circle in the center of each round. Top with one-sixth of the asparagus and mushrooms, forming a heaping pile. Pleat the dough around the vegetables to frame them. Brush the dough with the egg wash and sprinkle it with Maldon salt.
Transfer the galettes to the prepared baking sheet and bake until the crust is golden brown, about 20 to 25 minutes.
The assembled galettes can be frozen, tightly wrapped, for up to 1 month. Thaw slightly before baking.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.
Recipe courtesy of Nichole's Fine Pastry & Café, Fargo, ND