Cabbage, Apple & Onion Tart

As I mentioned on facebook, Nick reminded me around lunchtime on Monday that his office was throwing a party that night and we needed to bring a side dish. That request was just the push I needed to see if I could bake this Savoy Cabbage, Apple, Onion & Gruyere Rustic Tart, one that I’ve been ogling over for months, during Dylan’s nap time and not show up to the party covered in flour. I pulled it off – phew.

This recipe comes from a new favorite book of mine, The Fresh & Green Table: Delicious Ideas for Bringing Vegetables into Every Meal, written by Susie Middleton who happens to live down the street. I first baked her Roasted Ratatouille Tart with Goat Cheese & Mint this summer and have wanted to try a fall version ever since.

SAVOY CABBAGE, APPLE, ONION & GRUYERE RUSTIC TART
from The Fresh & Green Table: Delicious Ideas for Bringing Vegetables into Every Meal

For the egg wash
1 egg yolk
2 tbsp heavy cream

For the filling
1 tbsp extra-virgin olive oil
2 tbsp unsalted butter
1 medium onion, cut crosswise into thin slices
kosher salt
3 cups savoy cabbage, thinly sliced
1/2 golden delicious apple, unpeeled, cored, and cut into thin slices (I used a gala)

For the tart
1 cup grated Gruyere
1 tsp lightly chopped fresh thyme
1 disk savory rustic tart dough (see recipe below)

1. Preheat oven to 400 and position a rack in the center.

2. To make the egg wash: In a small bowl, whisk together the egg yolk and cream, set aside.

3. To make the filling: In a medium skillet, heat the olive oil and 1 tbsp of the butter over medium-low heat. Add the onion and a pinch of salt, cover, and cook, stirring occasionally, until the onion is limp and translucent, 5 minutes. Uncover, raise the heat to medium, and cook, stirring occasionally, until the onion is golden brown, another 6-8 minutes. Transfer the onion to a plate to cool.

4. Add 1/2 tbsp of the butter to the pan, raise the heat to medium-high, and add the cabbage and a big pinch of salt. Cook, tossing with tongs occasionally until cabbage is limp and nicely browned in spots all over, about 5 minutes. Transfer the cabbage to a separate plate to cool.

5. Add the remaining 1/2 tbsp of butter, add apples slices, season with a pinch of salt, and spread into a single layer. Cook for 2 minutes, flip, cook another 2 minutes. Transfer to plate to cool.

6. To make the tart: Line a large baking sheet with parchment and roll out chilled savory tart dough to a 12″ circle using plenty of flour. Place dough on baking sheet.

7. Sprinkle 1/4 cup Gruyere over the dough, leaving a 2″ border around edges. Top with 1/2 cabbage, 1/2 onion, sprinkle with a little thyme, and another 1/4 cup Gruyere. Repeat with the remaining cabbage and onion, and sprinkle again with a little thyme and another 1/4 cup cheese. Arrange the apple in the center. Sprinkle with thyme and remaining Gruyere.

8. Pleat and fold the edges of the dough, brush the edges with egg wash and bake until nicely golden about 38-40 minutes. Let cool for 5 minutes but eat warm.

SAVORY RUSTIC TART DOUGH
*makes 2 crusts but you only need 1 for tart

2 cups unbleached all-purpose flour plus more for dusting
1/2 tsp table salt
1 cup very cold unsalted butter, cut into 1/2″ cubes
1/4 cup ice water

1. In the bowl of a food processor combine flour and salt, pulse. Add the butter. Pulse 20 times or until the butter is the size of tiny pebbles. With the motor running, stream in ice water. Stop the motor. Pulse 6-8 times until the mixture leaves the sides of the bowl.

2. Turn mixture onto floured counter and knead it to form a dough. You simply want to bring all the crumbs together and make it smooth.

3. Divide the dough in half, shape each into a disc about 1″ thick, wrap with plastic, and refrigerate for at least 1 hour up to 2 days.