Onion Jam Tart with Cheddar Crust

Jammy onions require a crust that can stand up to their bold flavor, which is how this recipe came to be. Packed with sharp cheese, the cheddar pastry may remind you of a cheese straw. In fact, the whole tart may remind you of your favorite parts of a cheese board, where you often find balsamic onion jam, sliced fruit, and, of course, a perfectly sharp cheddar. Thinly sliced apples and pears top off the sweet and savory goodness before it heads to the oven.

As an appetizer, this tart can certainly take the place of a cheese board or accompany charcuterie. For lunch, it pairs well with a simple salad. As a side dish, consider serving it alongside pork loin or nicely crusted pork chops. Basically, whenever you’re in the mood for a warm, delicious tart, the timing will be right for this!

Ingredients

Pastry

1 ¼ cups all-purpose flour
¼ teaspoon salt
6 tablespoons unsalted butter
¾ cup grated sharp white cheddar
3 to 4 tablespoons ice water
1 egg (for egg wash)

Filling

3 yellow onions
3 tablespoons olive oil
½ teaspoon dried thyme
½ teaspoon salt
¼ cup balsamic vinegar
¼ cup light brown sugar
1 sweet-tart apple such as Lady Alice or Pink Lady variety
1 small Bosc pear
Lemon juice (optional to prevent slices from browning)
1 tablespoon butter

Begin by making the cheddar pastry dough. Combine the flour and salt in a food processor and pulse a couple of times to combine. Cut the cold butter into cubes and add to the flour, pulsing until the butter is reduced to pea-size bits. Add the grated cheddar and pulse to combine until the mixture resembles breadcrumbs. Slowly add the ice water while pulsing the dough, using enough so that when you pinch a small amount, it holds together. Turn onto a work surface or plastic wrap and gently form into a cohesive disk. Refrigerate wrapped dough for at least 30 minutes.

In the meantime, begin preparing the balsamic onion jam by slicing the onions very thinly. Heat the olive oil in a skillet over medium heat, add the onion slices, and cook until they are softened and translucent, about 12 to 15 minutes, stirring occasionally. Add the dried thyme and salt, cook for a minute, then follow with balsamic vinegar and brown sugar. Cook about 15 minutes, or until the onions have become jammy and most of the liquid has evaporated. Set aside to cool.

Once dough has chilled, roll it to line a 9-inch tart pan with removable bottom, pressing gently into the fluted edges and trimming any extra around the rim. Return to the refrigerator covered and chill for 30 minutes.

Preheat the oven to 350 degrees. Prick bottom of crust with fork. Line the tart pan with aluminum foil and fill with beans or pie weights. Bake for 12 minutes, remove the foil, then bake for another 5 minutes. Remove from oven and let rest for 20 minutes. Raise the temperature to 375 degrees.

Thoroughly whisk the egg with 1 tablespoon of water to make an egg wash. Brush just enough on the entire crust to give it a light, even coat.

Before filling the tart shell, peel and thinly slice the pear (cross-wise) and apple, making sure to remove core and seeds first. To prevent browning, you can add them to a bowl with a little diluted lemon juice as you slice.

Spoon the cooled onion jam into the bottom, spreading it to cover, then arrange fruit slices on top in two concentric circles leaving some of the jam exposed. (You may not need all of the slices.) Brush a half tablespoon of melted butter on the fruit.

Bake for about 30 minutes, or until the fruit is tender and the crust is deep golden. (After 20 minutes of baking, I like to brush fruit slices with additional melted butter.)

Serve warm.