To make the flatbreads, combine all of the flatbread ingredients in the bowl of a heavy-duty stand mixer fitted with the dough hook.
Mix at low speed until the dough comes together and pulls away from the sides of the bowl, about 2 minutes.
Cover the bowl with plastic wrap and let the dough rest for 30 minutes.
After the dough has rested, mix it again, on low speed using the dough hook, until soft and smooth, about 3 minutes.
Place a piece of plastic wrap directly on the dough's surface, and cover the bowl with a towel.
Let the dough rise again, until it is very light and slightly puffed, about 1 hour.
Gently punch down the dough and turn it onto a lightly-floured surface.
Using additional flour as needed, divide the dough into 4 equal pieces and shape each piece into a small ball.
Place the dough balls on a baking sheet and cover with a towel; refrigerate for about 45 minutes.
For the topping, heat the oven to 500 degrees F for at least 45 minutes.
If using a pizza stone, place it in oven to heat up.
(If you don't have a pizza stone, place a large, heavy baking sheet upside down in the oven to heat up).
Meanwhile, working on a lightly-floured surface, stretch each ball of dough to 9-inch round.
Place 1 round on a floured pizza peel (or a rimless baking sheet dusted with flour) and brush lightly with some of the olive oil.
Season to taste with the sea salt and pepper and top with one portion of the arugula.
Drizzle a little more olive oil on top of the arugula and top with one portion each of the sliced pear, cheese and pancetta.
Slide the flatbread onto the hot pizza stone or upside-down baking sheet and bake, until the crust is golden brown and crisp and the cheese is melted, rotating it once or twice, about 10 to 11 minutes.
Repeat with the remaining flatbreads; serve.
Make ahead: The flatbreads can be assembled and baked up to 8 hours ahead of time and kept refrigerated.
Bring them to room temperature before serving.