Caramelized Fennel Flatbread
2 1/4 teaspoons active dry yeast (a 1/4-ounce package)
1/2 cup warm water (105-115 degrees F)
3/4 cup all-purpose flour, plus a little extra if necessary
3/4 cup white whole-wheat flour
1 large egg
1 tablespoon extra-virgin olive oil
1 1/2 teaspoons salt
For the topping:
2 tablespoons olive oil
1 fennel bulb, white part thinly sliced
2 tablespoons coarse-grain dijon mustard
1/4 cup grated parmigiano-reggiano cheese
1In a small bowl, stir together the yeast and warm water. Let this mixture stand it starts to get foamy, about 5 minutes.
2 In the bowl of an electric mixer, combine the flours, then add the yeast mixture. In a separate small bowl, whisk together the egg, olive oil and salt to combine, then add this to the flour and yeast mixture in the electric mixer bowl. Using the dough hook, mix on medium speed to combine, then increase the speed and mix on medium-high speed to knead the dough, about 3 minutes. You may have to add more flour to keep the dough smooth and elastic; if you add more flour, sprinkle it in gradually. You may have to add up to another 1/4 cup.
3 Transfer the dough to an oiled bowl and turn to coat. Cover with a clean dishtowel and let it rise until doubled in size, about 1 to 1 1/2 hours.
4 While the dough rises, heat 2 tablespoons olive oil in a large heavy skillet. Add the slices of fennel bulb and a pinch of salt. Cook over medium-low heat until the fennel is golden brown and caramelized, about 30 minutes. Set aside.
5 When the dough is almost finished rising, preheat the oven to 375 degrees F with a rack in the middle.
6 Gently deflate the dough and turn it out onto a piece of lightly floured parchment paper. Roll the dough out to a roughly 15×12 inch rectangle, then transfer the piece of parchment (with the dough on it) to a heavy baking sheet. Spread the dijon mustard all over the dough, leaving about a 1/2-inch border around the edge.
7 Sprinkle with half the grated cheese, then sprinkle the caramelized fennel all over the dough. Top with the remaining half of the grated cheese.
8 Bake until the crust is golden brown, about 30 to 35 minutes. Remove from the oven and sprinkle the fennel fronds evenly over the top; they’ll wilt ever so slightly with the residual heat coming off of the flatbread.
9 Cut into squares and serve warm or at room temperature.