The Easiest Onion Tart

There's no reason to relegate onions to the background. We talked to David Tanis about making them shine and we got his recipe for a delectable onion and bacon tart.

Onion and Bacon Tart
An onion tart is a beautiful way to show off the bulb’s many virtues. A classic example is this pizza-like tarte flambée or Flammeküche. An Alsatian specialty, it has only a few ingredients: onions, crème fraîche, fromage blanc, and bacon. Originally it was a frugal treat on bread-baking day, made from a scrap of bread dough and baked on the stone floor of the village’s communal wood-fired oven.

1/2 cup lukewarm water
1 teaspoon active dry yeast
1 1/2 cups all-purpose flour
1/2 teaspoon salt
1 1/2 tablespoons butter, melted, or olive oil

2 tablespoons butter or olive oil
3 large onions (about 1 1/2 pounds), sliced 1/8 inch thick
Salt and pepper
1/2 teaspoon caraway seeds
2 garlic cloves, grated or minced
1/4 pound thick-sliced smoked bacon, cut into 1/4-inch-wide lardons
4 ounces fresh ricotta
1/2 cup crème fraîche
A splash of milk if needed

 To make the dough, pour the water into a medium bowl and stir in the yeast. 
Stir in 1/4 cup of the flour and let the mixture get bubbly, 10 to 15 minutes. 
(You can made the dough with a stand mixer if you like.)

Add the salt, melted butter, and the remaining 1 1/4 cups flour and stir until the dough forms a rough ball. Then turn the dough out onto a lightly floured surface and knead for about 5 minutes, until smooth. Cover the dough with a damp towel or plastic wrap and let rise until doubled in size, about 1 hour. (Or transfer the dough to a zippered plastic bag and let rise in the refrigerator for several hours, or overnight.)

To make the topping, melt the butter in a large skillet over medium-high heat. Add the onions and cook, stirring occasionally, until wilted and lightly browned, about 5 minutes. Season generously with salt and pepper. Stir in the caraway seeds and garlic and cook for 2 minutes more. Let cool to room temperature.

Put the bacon in a small pan and cover with 1 inch of water. Simmer for 2 minutes, then drain and cool.

Heat the oven to 375 degrees. Punch down the dough, transfer to a lightly floured surface, and knead into a smooth ball. Let relax for a few minutes.

Using a floured rolling pin, roll out the dough to a circle about 12 inches in diameter. Transfer to a 12-by-17-inch baking sheet lined with parchment. Stretch the dough to an elongated oval about 11 inches by 15 inches.

Mix the ricotta with half the crème fraîche and dab spoonfuls of the mixture evenly over the dough. Spread the cooked onions over the dough, leaving a 1/2-inch border all around. Top with the bacon, scattering it evenly. Drizzle the tart with the remaining crème fraîche. (Beating the crème fraîche with a fork should loosen it enough for drizzling; otherwise, thin with a little milk.)

Bake the tart for 30 to 35 minutes, turning the baking sheet around if necessary for even cooking, until the crust is well browned. Cool on a rack for a few minutes and serve warm, or let cool and serve at room temperature. 

Makes 4 to 6 servings