This came from a magazine I’d been disappointed the whole year I’ve received it, “Eating Well”. But this tart was so beautiful and appealing and we followed the recipe pretty exactly and it came out perfectly. It helped to have a detail-oriented nine-year old girl to arrange the vegetables, as well as a committee to decide exactly where they should go. I learned with this recipe that my V-slicer was NOT made to cut raw sweet potatoes. Bent prongs. This was a great part of our meal (and excellent left over for lunch) but I would also make it as a vegetarian meal itself, with a salad on the side.
¾ cup walnut pieces
1 ¼ cups whole wheat pastry flour
1 ¼ cups all purpose flour
2 - 3 tablespoons chopped fresh thyme and/or rosemary
salt and pepper
½ cup olive oil, plus more
7 tablespoons ice water
1 ½ lbs. sweet potatoes, peeled, sliced into ¼ inch thick rounds
1 ½ cups thinly sliced red onion (1 large)
1 cup fontina cheese, shredded
1 large egg white, beaten with a bit of water
Pulse the walnuts in a food processor until finely ground. Add the flours, 2 tablespoons of herbs, and about ¾ teaspoon each of salt and pepper and pulse until combined. Add ½ cup olive oil and water and process until it begins to form a ball – dough will seem wetter than most pastry doughs. Remove from processor and form into a ball, then pat into a disk. Wrap in plastic and refrigerate for at least 15 minutes.
Toss together sweet potatoes, 1 tablespoon oil, some salt and pepper on a baking sheet. Toss onions on a smaller baking sheet with another drizzle of oil. Roast for 10 minutes at 425 degrees. Remove to cool and reduce oven to 375.
Place dough disk on a floured work surface or silicone mat, with parchment paper on top. Roll out to a 15-inch circle, adding flour to prevent sticking if necessary. Flip over and transfer to a baking sheet, with the parchment paper on the bottom. Leaving a 2 inch border, sprinkle the cheese evenly over the crust. Arrange the sweet potatoes and onions in a bull’s eye pattern, with larger potato circles on the outer ring, then a ring of onions, and an inner ring of smaller potatoes.
Fold the outer rim of the crust up and over, pleating. The filling will not be completely covered. Brush the crust with the egg wash. Drizzle vegetables with a bit more oil and sprinkle with the remaining herbs.
Bake until lightly browned on the edges, and vegetables can be easily pierece with a fork (recipe said 50 minutes, but ours was done in 30). Cool 10 minutes before serving.