This tart makes use of whatever hearty winter vegetables you have on hand. We focused on sweet root vegetables, but you could also use cauliflower, cabbage wedges, potatoes or broccoli.
Preheat your oven to 400 F. Butter an 8- by 11½-inch rectangular or 12-inch circular tart pan with removable bottom and set aside. Line a rimmed baking sheet with parchment paper.2.
In a large bowl, toss the root vegetables with the olive oil, honey, fennel, coriander and 1 teaspoon kosher salt. Arrange them in a single layer on the baking sheet and transfer to the oven. Bake, turning the pan halfway through cooking time, until tender and golden, 30 to 35 minutes.3.
Meanwhile, make the filling: In a medium bowl, stir together the ricotta, feta, egg, walnuts, scallions and remaining 1/2 teaspoon salt. Set aside.4.
Set the buttered tart pan on a rimmed baking sheet. Take one sheet of phyllo and lay it in the pan so that it drapes over the sides. (How this works depends on the shape of your pan. If rectangular, this will be straightforward. If round, you'll need to lay the phyllo diagonally and rotate the sheets so that the whole pan is eventually covered.) Brush the first sheet of phyllo with butter. Lay the second piece over that, then butter. Repeat until all 8 sheets are used.5.
Spoon the filling into the tart and spread evenly. Arrange the roasted vegetables on top, then sprinkle with thyme. Bake until the phyllo is golden-brown, and the center is set, 35 to 40 minutes.