For the crust
- 1 1/4 cups flour, plus more for the work surface
- 1/2 teaspoon fine sea salt
- 1/4 cup chilled solid vegetable shortening, preferably Crisco, cut into small pieces
- 4 tablespoons (1/2 stick) chilled unsalted butter, cut into small pieces
- 3 to 8 tablespoons ice water
For the filling
- One 14-to-16-ounce sweet potato
- 1 tablespoon extra-virgin olive oil, plus more for garnish
- Grated zest of 1 orange
- Fine sea salt
- Freshly ground black pepper
- 2 tablespoons cane, sorghum or maple syrup2 ounces blue cheese, crumbled
For the crust: Combine the flour and salt in a food processor, then add the vegetable shortening and butter. Process for 8 to 10 seconds or just until the mixture resembles coarse meal.
Add the ice water 1 tablespoon at a time as you pulse, using just enough so the dough holds together without being sticky or crumbly; you might not use all of it. Transfer the dough to a work surface and shape into a disk 4 to 6 inches in diameter; wrap in plastic wrap. Chill until the dough is firm and evenly moist, about 30 minutes.
Line a rimmed baking sheet with parchment paper or a silicone liner.
Flour a clean work surface and a rolling pin. Place the dough disk in the center of the floured surface. Starting in the center of the dough, roll out to, but not over, the upper edge of the dough. Return to the center and roll down to, but not over, the edge closest to you. Lift the dough, giving it a quarter turn, and lay it on the work surface. Continue rolling, repeating the quarter turns, until you have a dough round that's about 12 inches wide.
Place on the lined baking sheet. Refrigerate until firm, about 30 minutes.
Meanwhile, preheat the oven to 375 degrees.
For the filling: Peel the sweet potato and use a mandoline (preferred) or very sharp knife to cut it into thin slices, between 1/8 and 1/4 inch thick. Transfer to a medium bowl and drizzle with the oil, then add the orange zest. Season with salt and pepper to taste. (Be conservative with the salt; the blue cheese will be salty.) Toss to coat evenly, taking care not to break the slices.
If starting with cold syrup, heat it in the microwave on LOW just to room temperature, about 10 seconds. Brush all of the syrup on the chilled round of dough to within 1/2 inch of the edge. Scatter the blue cheese evenly over the syrup.
Starting at the outer edge, layer the sweet potato slices over the cheese, overlapping them in tight concentric circles and keeping in mind that they will shrink during baking. Bake until the crust is golden brown and the sweet potatoes are slightly curled and tender, 30 to 35 minutes.
Place the baking sheet on a wire rack to cool for at least 5 minutes before transferring the tart to a platter. Slice and serve warm or at room temperature.
NUTRITION Per serving: 180 calories, 3 g protein, 18 g carbohydrates, 11 g fat, 5 g saturated fat, 15 mg cholesterol, 190 mg sodium, 1 g dietary fiber, 4 g sugar