Tomato-Onion Tart

from the San Francisco Chronicle Thursday Wine Section

via Katherine Koelsch Kriken

serves 8 as a first course, many as an hors d'oeuvre

1 large yellow onion

1 tablespoon extra virgin olive oil plus additional as needed

2 sprigs thyme

kosher salt

ground black pepper 2 or 3 medium-sized tomatoes

1 sheet pre-packaged puff pastry dough, defrosted (about 7 or 8 ounces) 

3 ounces pitted Kalamata olives, thinly sliced or chopped

3 ounces grated smoked provolone, Gouda or mozzarella

1/4 cup plus 2 tablespoons Panko bread crumbs chopped parsley or thyme (optional)

Preheat the oven to 400 degrees.

Cut onion in half, peel and slice thinly lengthwise (from root to stem end). Add oil to medium skillet over medium to medium-low heat. When skillet is hot, add the thyme sprigs and onions; season to taste with salt and black pepper. Cook, stirring occasionally, until onions are soft and golden and moisture is evaporated (the volume should be decreased by 1/3 to 1/2), about 20 to 25 minutes. Remove the thyme when it becomes aromatic and has perfumed the onions. Remove pan from the heat and set aside. The onions can be made a day ahead and refrigerated. Meanwhile, cut tomatoes into 1/4-inch slices; spread slices out on a plate to drain (don't stack more than a few slices together).

Unfold the puff pastry dough onto a flour-dusted board or piece of parchment paper. Roll out slightly to make the dough about 1/8-inch thick. Use a sharp knife to cut dough in half or into individual-sized tarts. To make an optional crust edge, trim a 1/2-inch piece from each edge, moisten with water and flip it over on top of the large piece. Trim the excess lengths of crust so it fits; gently press the crust to seal it to the bottom of the tart. Prick the dough well with a fork (except the edges). Bake until light golden and cooked through, about 25 to 30 minutes. The crust edge, if added, should puff up.

Allow the puff pastry to cool slightly. Spread the onions over the pastry and top with the olives. Combine the grated cheese and panko. Cover the onions with about half of the cheese mixture; sprinkle the cheese with parsley or chopped thyme. Discard any excess liquid from the tomatoes. Arrange the tomato slices in overlapping rows on top of the cheese and season to taste with salt and pepper. Finish with the rest of the cheese mixture. Bake until onions are heated through, the tomatoes are warm and juicy and the cheese is melted and browned, about 7 to 10 minutes.

This vegetarian tart is a delicious accompaniment to grilled lamb or beef or with fish such as salmon, tuna or halibut. Great as well with drinks as appetizer. Heavenly when served warm but also good at room temperature.