Carta Di Musica with Bottarga and Butter
For the dough:
½ cup all-purpose flour, plus extra for dusting
½ cup very fine semolina flour
¼ teaspoon kosher salt
For the sandwiches:
3 tablespoons unsalted butter, at room temperature
3 ounces Sardinian gray mullet bottarga, very thinly sliced at the last minute on a mandolin
Maldon or another flaky sea salt
1 or 2 dried pequin chilies, crumbled, or pinches of red pepper flakes (optional)
Extra Virgin olive oil for drizzling
pizza stone, mandoline
Make the dough:
Mix the flours and salt in a mixing bowl and make a well in the center. Slowly pour in ¼ cup room-temperature water, stirring it in with a fork. Use the fork to mix gradually, adding more water if necessary, until all the flour is incorporated and you have a smooth, barely moist, firm but pliable dough.
Lightly dust a work surface with flour, put the dough on the work surface, and knead it until it’s as smooth as a baby’s bum, about 7 minutes.
Roll the dough into a log that’s about 6 inches long and 2 inches thick. Wrap it in plastic wrap and let rest for at least 2 hours or overnight in the fridge.
Preheat the oven to 450F. Put an oven rack in the lower third of the oven and remove any other racks. Put a pizza stone on the rack and let it get good and hot, at least 20 minutes. If it’s not really hot, your dough won’t puff up like a balloon, which is essential.
Dust your work surface with plenty of flour. Cut the log into six 1-inch thick pieces and cover them with a barely damp kitchen towel. Working with one at a time, on the floured surface, roll each disk into a thin, even circle about 6 inches in diameter. Even thickness is important; otherwise, the circles won’t puff up.
Make the carta da musica:
One or two at a time, carefully lay the disks on the hot pizza stone so they lie completely flat, with no folds, bumps, or creases, or (guess what?) they won’t puff up. Bake until they begin to bubble, then start to puff, about 4 minutes. Once they do, flip them gently but swiftly with a spatula and continue to cook until they have completely inflated, a minute or two. Remove them from the oven (don’t turn it off) and immediately cover them with a clean cloth. Use a pan, round tray, or rolling pin to flatten them, forcing the air out. Let them cool to the touch with the towel still on top.
Use a knife to cut around the edges of each circle to separate it into the 2 thin rounds that separated during the puffing up, and stack them one on top of the other. Try to keep them intact, because it’ll be a bit easier to finish the dish that way, but if you don’t end up with 2 perfect circles, no matter.
Working in batches, bake the 12 circles on the hot stone once again, turning them over once, until they’re crispy and have golden-brown patches here and there, 1 to 1 ½ minutes per batch. Let them cool completely.
Generously butter one side of each of the crispy disks (a pastry brush makes this easy). Sprinkle the bottarga over 6 of the disks. Sprinkle a little salt and crumbled chili over each one, then drizzle with the tiniest bit of olive oil. Make 6 sandwiches, topping the bottarga with the remaining disks, butter side down.
Gently break each one in half and eat straightaway.