Have I raved about In the Small Kitchen enough yet? I’ve always been a fan of Big Girls, Small Kitchen, but I’m loving their cookbook. All of the recipes are simple, require relatively little space (Cara and Phoebe cooked out of tiny NY kitchens, after all!) and are absolutely delicious. I tried this Sexy-Ugly Onion Tart a couple weeks ago and even Simone ate some of it. Amazing. Next time, though, I will add some sauteeed mushrooms for extra bulk. I went ahead and included them in the recipe below.
2 tablespoons unsalted butter
2 onions, halved and sliced into thin half moons
1/2 lb cremini mushrooms, thinly sliced
1 teaspoon fresh thyme leaves, plus a little extra for garnish)
1/4 teaspoons salt
1 cup whole-milk ricotta
1 egg yolk
Pie dough for 1 pie crust
In a large cast-iron skillet or Dutch oven, melt the butter over low heat. Add the onions and cook, stirring occasionally, for about 45 minutes, until caramelized. The onions should be deep brown and sweet. Watch to make sure they don’t burn. When they are almost done, add the mushrooms and saute until just soft. Add the fresh thyme and the salt, and let cool. Whisk the ricotta and the egg yolk together in a small bowl and set aside.
Lightly flour a clean work surface and roll out your die dough until it is large enough to cover a 9-inch fluted tart pan. (I don’t have a tart pan, so I used a pie dish). Roll up the dough on your rolling pin and slowly unroll on top of the tart. Use your fingers to press the dough into the tart and a paring knife to trim off any excess. Preheat the oven to 400°.
Use a spatula to spread the ricotta mixture evenly across the surface of the crust. Arrange the onions and mushrooms on top. Bake for 25 to 30 minutes, until the ricotta filling is firm and the crust is golden. Let the tart cool in the pan and garnish it with thyme leaves. Will serve 4 generously as a main dish, or 8 as a side.