Just in time for the Holidays! Estate Chef Tom Stafford shares the Autumn Squash and Caramelized Onion Tart recipe, a seasonal favorite at our St. Helena Tasting Room. This recipe is shared at the request of  our Vine Cliff Wine Club members.


1 cup whole wheat flour
2 tsp. kosher salt
1 tsp. sugar
1 cup all-purpose flour, plus more for surface
12 Tbsp. chilled unsalted butter, cut into pieces

2 Tbsp. peanut oil
2 Tbsp. unsalted butter
4 medium yellow onions, thinly sliced
3 Tbsp. Brown Sugar
2 Tbsp. Kosher salt
3 garlic cloves, minced
2 Tbsp. Dijon mustard
2 Tbsp. of Harissa Paste
4 oz. grated Gouda cheese
½ small butternut squash (a lengthwise half, about 1¼ lb.), seeds removed
½ delicata squash (about 1 lb.), halved lengthwise, seeds removed
½ kabocha squash (about 1 lb.), halved lengthwise, seeds removed
1 small red onion
4 sprigs thyme
2 Tbsp. unsalted butter
Flor de Sel Finishing Salt



In a bowl, whisk together the flour, salt and sugar. Using a knife, cut in the butter until pea-size crumbs form. Add 1 Tbs. of water at a time and mix with your hands, adding more water as needed until the dough comes together. It should be moist but not sticky.

Turn the dough out onto a lightly floured surface, divide into 2 balls and shape each into a 5-inch disk. Cover separately with plastic wrap and refrigerate for at least 1 hour.

On a lightly floured surface, roll out each dough disk into a 12-inch round about 1/8 inch thick. Using a small knife, trim the uneven edges. Transfer each round to a parchment-lined baking sheet and refrigerate for at least 30 minutes. Use as directed in your tart recipe. Makes enough dough for two 10-inch tarts.


Preheat oven to 350°. Place 2 Tbsp. oil in a large skillet to coat bottom and add yellow onions; season with kosher salt. Set skillet over medium heat and cook onions, stirring occasionally and making sure to scrape bottom of pan, until very soft and deep golden brown, 15–20 minutes. Add garlic and cook, stirring occasionally, until onions are caramelized, 25–30 minutes. Finish with sprinkling brown sugar. Spread out and let cool.

Brush mustard over chilled dough, then smear with harissa. Stir cheese into caramelized onion mixture and spread across crust in an even layer.

Using a mandoline or very sharp knife, thinly slice both squashes crosswise. Cut red onion in half lengthwise, then thinly slice crosswise with mandoline.

Arrange squash in concentric circles, with rounded edges facing up, starting from the outside edge, leaning slices against the crust, and working your way inward.

Drizzle 2 Tbsp. oil over vegetables and season with kosher salt.

Bake tart until edges of vegetables are browned, and crust is golden brown, about 1 hour – 1 hour 15 min.

Melt thyme and butter in a small saucepan and cook just until butter is bubbling. Brush over tart with a pastry brush and sprinkle with finishing salt.