thanksgiving tradition – the squash & caramelized onion tart
It’s the week of Thanksgiving! In the US, this is a holiday full of tradition. Most people have some expectation of what thanksgiving dinner looks like. We all have memories and experiences that are fun to repeat each year. It’s the one day a year that the traditional turkey dinner, complete with mashed potatoes, stuffing, and gravy is served.
Beyond those four cornerstone dishes, families have traditions of sides that accompany dinner every year. A few years ago, Mike and I decided to try a recipe that I found in Bon Appetit, called the Squash and Caramelized Onion Tart. It was a hit! We’ve made it every year since. It does require a bit of work on a mandoline (ideally), but it is more than worth the effort. In fact, I always say that I’d make this any time of year because it’s so good!
If you’re looking for a new side that incorporates traditional thanksgiving flavors (squash, onion, sweet potato, thyme), but want a different take on these traditional ingredients, I think you’ll love this recipe.
Squash & Caramelized Onion Tart
This is a staple of our Thanksgiving table. For slicing the vegetables, a madolin is a must a finished looking tart and tender vegetables. Also, this is best baked in a tart pan, as removing the edge makes it possible to cut and serve.
Ingredients
CRUST
- 1 cup whole wheat flour
- 1 TSP kosher salt
- 1 cup all purpose flour, plus more for surface
- 10 TBSP chilled butter, cut into pieces
FILLING & ASSEMBLY
- 4 TBSP olive oil
- 4 medium yellow onions, thinly sliced with a mandolin
- kosher salt
- 3 garlic cloves, thinly sliced
- 2 TBSP dijon
- pinch of cayenne pepper
- 4 oz. Gruyere cheese, coarsely grated
- 1/2 small butternut squash, peeled and halved lengthwise and seeds removed
- 1 delicata squash, halved lengthwise and seeds removed
- 1 small sweet potato
- 1 small red onion
- 2 sprigs of thyme
- 2 TBSP butter
- flaky sea salt
Instructions
Whisk whole wheat flour, salt, and 1 cup of all purpose flour in a large bowl to combine. Add butter and work into dry ingredients with your fingers, until the largest pieces are no bigger than a nickel. Drizzle 6 TBSP of ice cold water, working with your fingers to combine until a shaggy dough forms. Turn out onto a work surface and knead until only a few dry spots remain. Press into a disc and wrap tightly in plastic. Place in refrigerator and chill for at least 2 hours but up to 3 days.
Roll out the dough on a lightly floured surface until about 1/8" thick. Transfer to the tart pan. Gently shape in the pan and trim excess. Freeze 15-20 minutes until firm or cover and chill up to 12 hours.
Filling & Assembly
Preheat oven to 350F and place rack in lower third of the oven. To a large skillet, add 2 TBSP olive oil over medium heat. Add the onions and season with salt. Cook until very soft and deep golden brown 15-20 minutes. Add garlic and continue to cook for a total of 25-30 minutes until caramelized and deeply brown. Let cool.
Brush mustard over chilled dough, then sprinkle with cayenne. Stir cheese into caramelized onions and spread across crust in an even layer. Using a mandolin, thinly slice squashes crosswise. Thinly slice sweet potato and red onion in half lengthwise. Arrange vegetables atop the dough in concentric circles, with rounded edges facing up, starting from the outside edge and working your way inward. Drizzle remaining 2 TBSP olive oil over top and season with salt.
Bake until edges of vegetables are browned and crust is golden brown, 75-90 minutes. Melt butter and thyme leaves in a small saucepan and cook just until the butter bubbles. Brush over tart and sprinkle with flaky salt.
Notes
Inspired by: Bon Appetit