1 cup grated smoked mozzarella or cheese substitute (See note)
Note:You may substitute almost any kind of cheese. Weaver’s Orchard Farm Market carries a smoked gouda that would work well here. However, Swiss cheese would also be delicious. I whipped up a little vegan cheese for my tart, because I wanted to test a vegan version of the tart too.
Preheat the oven to 400 degrees. Position a rack in the middle of the oven.
To make the filling: In a medium skillet, heat the olive oil and the butter over medium-low heat. Add the onion and the salt and cook until translucent, about 3- 4 minutes. Raise the heat to medium and add the cabbage, cooking everything until the cabbage is wilted, about 5 minutes.
All the onion/cabbage mixture to cool for a few minutes.
To assemble the tart: Line a baking sheet with parchment or silicone mat. Unroll the pie crust onto the baking sheet. Sprinkle or spread half the cheese onto the crust, allowing a two-inch margin or border around the whole edge. Cover that with half the onion/cabbage mixture. Sprinkle with half the sage. Repeat that, for another layer. Arrange the apple slices on top. Pleat and fold the edges of the pie crust dough up and over the outer edge of the filling all the way around the tart.
Bake until golden all over, about 38 to 40 minutes. Let cool about 5 minutes before slicing and serving.