This recipe comes from Brett Emerson at San Francisco's Catalonian-inspired Contigo restaurant. Emerson routinely riffs on Spanish tradition with local California produce, including this coca with an assortment of fresh peppers. Although cocas usually don't have cheese, this version features a few handfuls of young Manchego. You'll have to enjoy it fresh from the oven so that the cheese doesn't cool off, but that shouldn't be a problem.
3 large yellow onions, sliced into thin half-moons
Salt, to taste
2 tablespoons chopped fresh thyme leaves
3 peppers, sliced thin (sweet bell peppers or other heirloom varieties such as gypsy, cubanelle, etc.)
1/2 pound Manchego cheese, cut into 1/2-inch cubes (use a young Manchego, aged less than 6 months)
1/4 pound pancetta or bacon, cut into small squares or 1-inch lengths, depending on thickness
2 tablespoons chopped fresh oregano leaves
Preheat the oven (and pizza stone, if you have one), to 500 degrees, and take the dough out of the refrigerator to warm up.
Heat the olive oil over medium heat. Add the sliced onions, along with a hefty pinch of salt. Cook for about 1 hour, or until caramelized, about the color of cornflakes, stirring occasionally. Add the thyme in the last 5 minutes of cooking. Allow to cool, then puree in food processor (this step can be done in advance).
To assemble the coca, divide the dough into quarters, and remove one portion of it (keep the remaining portions covered). Roll out the dough into an oval shape, roughly 12-by-6 inches and place on a parchment-lined cookie sheet or a cornmeal-sprinkled pizza peel (if you're using a pizza stone). Spread a thin layer of onion puree on the dough, leaving a 3/4-inch border. Lay on as many pepper slices as you feel is appropriate, and sprinkle cheese cubes on dough evenly. Lay on bacon or pancetta pieces. Bake, either on the cookie sheet or transferring onto the pizza stone, until the dough is browned, about 5 minutes.
Pull coca out of oven and sprinkle on chopped oregano and salt. Repeat with remaining dough and filling.