Heirloom Tomato, Sweet Corn and Thyme Tart

For the pastry:
Combine the flour, salt, black pepper and thyme leaves in the bowl of a food processor. Pulse to combine. Add the butter and pulse until it resembles coarse meal. With the processor running, add the water 1 tablespoon at time until the mixture forms a ball. Press the mixture into a deep, 10 inch tart tin with a removable bottom. Place in the freezer for 15 minutes. Preheat oven to 400 degrees F.

Remove the tart from the freezer and gently prick the bottom of the pastry several times with a fork. Line the pastry with parchment paper and top the paper with pie weights or dry beans. Bake on a cookie sheet for 30 minutes. Remove from the oven and set aside, removing parchment and weights once cool enough and safe enough to do so.

While the pastry bakes, make the filling.

In a large skillet, sauté the onion slices in 1 tablespoon of the olive oil on medium high. Allow onions to turn golden and caramelized. Remove onions from pan and allow to cool. Put the corn kernels into the pan along with the second tablespoon of olive oil. Sauté for 3-5 minutes, until corn is a little soft and slightly caramelized. Finally add the remaining tablespoon of olive oil to the pan and add the tomatoes.

Cover the pan with a lid and allow the tomatoes to soften and the skins to pop. Cook covered for about 10 minutes, periodically stirring to allow for even browning. Remove the tomato mixture from the pan, put it into a bowl and allow to cool to lukewarm.

Grate the cheese and sprinkle on the bottom of the pastry. Layer half the onions on top of the cheese, then combine the remaining onions with the corn and tomatoes in the bowl. Fill the tart with this mixture, then return to the 400 F oven to bake for an additional 20 minutes, allowing the cheese to melt and the pastry to turn golden brown.

Remove from the oven and let it cool for 30 minutes prior to serving.