2 tablespoons chopped flat leaf parsley for garnish
Instructions
To make the crust: In the bowl of a food processor fitted with the "S" blade combine the teff flour, oat flour, and salt. Pulse until completely combined. Add the frozen butter pieces; pulse until the butter is broken up into small pea-size pieces. Sprinkle in 5 tablespoons of ice water and pulse again a few times to combine. Test the flour mixture by squeezing a small amount together in the palm of your hand. If it clumps together and holds its shape, move ahead to the next step. If not, add a bit more of the 2 tablespoons of ice water that is left, pulse, and check again.
*Transfer the dough to a large piece of plastic wrap, and shape it into a thick disk. Wrap the dough in the plastic wrap and refrigerate for about 30 minutes.
Preheat the oven to 375°F with a rack positioned in the center of the oven. Unwrap and gently roll the dough on a surface that has been lightly sprinkled with teff flour. All you want to do is get the tart crust to the basic size and shape of your 11-inch fluted tart pan with removable bottom. Then you can very gently lift the pastry into the pan and press together any cracks or breaks that may have formed. Press the crust all the way up the sides of the tart pan with your fingertips so that the edges are level with the top.
Prick the bottom of the crust all over with a fork, line with parchment, and fill with dried beans or pie weights. Put the tart pan on a baking sheet and bake about 10 minutes or until the edges look dry. Carefully remove the beans and parchment; bake until the bottom is set and appears to be dry, about 5-7 minutes more. Cool on the baking sheet on a wire rack.
To make the filling: Maintain the oven at 375°F. Cut the delicata squash in half, scoop out the seeds, and slice into ¼-inch-thick half-moons. Lay out in an even layer on a parchment lined baking sheet and drizzle with 2 tablespoons of extra virgin olive oil, salt, and pepper. Roast in the oven for about 10-12 minutes until the squash is tender and a fork easily slides into the flesh. Remove from oven and set aside.
While the delicata squash is roasting, heat 2 tablespoons of olive oil in a large cast iron or heavy-bottomed skillet over medium-high heat. Add the onions and a generous pinch of salt; cook, stirring frequently until the onions begin to wilt down and develop dark charred spots, about 10 minutes. Reduce the heat to medium-low, cover, and cook 8-9 minutes more until softened and caramelized, stirring every few minutes. Add 1 tablespoon of the balsamic vinegar and stir until it evaporates and glazes the onions. Transfer the onions to a large bowl and wipe out the pan.
Heat the remaining tablespoon of olive oil in the pan over medium-low heat. Add the garlic and cook about a minute, until fragrant and just beginning to turn golden. Increase the heat to medium-high and add the greens along with a pinch of salt. Toss over medium-high heat until the greens have wilted down completely, about 3-4 minutes. Sprinkle in the remaining tablespoon of balsamic vinegar and toss for about a minute until the vinegar cooks away. Transfer to the bowl with the onions and toss to combine.
Add the delicata squash, ¾ cup of the feta cheese, and a large pinch of red pepper flakes, and toss gently to combine. In a separate small bowl, beat the eggs along with a pinch of salt and pepper until combined and pour over the vegetable mixture. Gently toss to combine all of the ingredients.
Assemble the tart: Spread the filling evenly in the tart shell and scatter the remaining ¼ cup of feta cheese over the top. Bake the tart on the baking sheet in the 375°F oven for 25-30 minutes until the cheese is golden brown on top.
Remove the tart from the oven and transfer to a cooling rack for about 10 minutes. Carefully remove the outer ring of the tart pan and sprinkle the tart with fresh parsley. Slice and serve warm or at room temperature.
Notes
*The dough of this tart is completely different than a normal all-purpose flour dough and doesn't hold together the same. When you pour the dough from the food processor it is completely acceptable for it to be grainy and separated still. Simply pull it together with your hands and form it into a disk shape. The fridge will do the rest of the work for you.