For the topping:

For the dough: Combine the flour and salt in the bowl of a food processor; pulse to mix well. Line a large rimmed baking sheet with parchment paper or a silicone mat.

Combine the water and oil in a measuring cup and add to the flour mixture; pulse until a soft ball of dough forms. If the dough is too stiff (a hard-clay texture), add a tablespoon of warm water; pulse or process for about 15 seconds, until the dough is well kneaded.

Flour your hands well and lightly flour a work surface; transfer the dough to the work surface and cut the dough into quarters. Work with 1 quarter of the dough at a time and roll out to about a 12-by-4-inch rectangle; dust with flour as needed to keep it from sticking. Place on the prepared baking sheet; repeat with remaining dough. The 4 flatbreads should fit crosswise on the same sheet. Set aside.

For the topping: Adjust the oven rack to the lowest position; preheat to 500 degrees.

Heat 1 1/2 tablespoons of the oil in a lag toward the end of their cooking when they begin to turn brown.

Meanwhile, spread the 4 flatbread dough rectangles evenly with the apple butter.

Toss the kale with the remaining 1/2 tablespoon of oil and season lightly with salt and pepper.

Top each flatbread dough rectangle with the caramelized onion, spreading evenly; then the kale; then the sausage slices. Bake for 10 to 12 minutes, until the pizzas are brown in spots. Remove from the oven and scatter the cheese over the top. Serve hot.

Makes 4 individual flatbread pizzas or one 12-inch thin pizza (5 servings).