Upside Down Tomato Onion Tart

Read the entire directions, this recipe takes time and planning: however, it can be broken down into manageable stages.

Unfold puff pastry. Cut out a 10-inch round and chill until ready to use.

Preheat the oven to 225ºF. Slice tomatoes in half. Toss on sheet pan and dry vermouth. Place each half tomato skin side down. Place in oven and slow roast for 3 hours, until concentrated and have lost more than 50% of their moisture or more but still moist.

While the tomatoes are roasting prepare the onions. In the sauté pan melt butter over medium heat. Add the onions and cook slowly, allowing the onions to carmelize their sugars from the inside-out rather than browning the exterior. This will take time, up to 1 ½ hours. Keep an eye on them, stirring and adjusting temperature as necessary to develop deep flavor. If they happen to scorch or start to develop exterior browning, just add a tablespoon of water and adjust the temperature. When they have developed a deep amber color remove from heat and set aside.

Preheat oven to 425ºF. In a 9-inch cast iron skillet add the sugar and water. Cook over medium heat swirling to mix rather than stir until the sugar melts and the mixture bubbles and turns amber, about 7 to 10 minutes. Remove from heat and sprinkle with the Sherry vinegar using the swirling motion to combine.

Arrange the olive slices over the caramel. Arrange roasted tomatoes in a circular overlapping pattern to cover with cut side down. Sprinkle with thyme, salt, and black pepper. Add the layer of melted onions. Cut a vent into the puff pastry and top the tart, tucking in the sides of the pastry all around. Using a pastry brush, glaze the pastry by applying the beaten egg.

Bake until the pastry is golden, about 20 minutes. Let rest five minutes. Do not wait too long as the caramelized sugars will start to harden. Run a knife around the edge to loosen the tart from the pan. Turn tart onto a serving platter by placing a patter over and flipping upside down. Serve immediately.