Makes 4 sandwiches
For the pickled iceberg:
½ cup [120 ml] red wine vinegar
1 cup [240 ml] water
3 garlic cloves, minced
1 tablespoon granulated sugar
1 tablespoon fennel seeds
1 tablespoon dried oregano
1 teaspoon pimentón (smoked Spanish paprika)
2 teaspoons kosher salt
1 medium head iceberg lettuce, ragged outer leaves and core discarded, remaining leaves separated
For the sandwiches:
½ cup [120 g] pimento-stuffed green olives, finely chopped
1 tablespoon capers
⅓ cup [80 g] mayonnaise
4 individual sandwich rolls (preferably with sesame seeds on top), halved horizontally
¼ pound [113 g] thinly sliced aged provolone cheese
One 7-ounce [198 g] jar roasted red peppers, drained, rinsed, and patted dry with a paper towel
½ pound [227 g] fresh mozzarella cheese, thinly sliced
Place the vinegar, water, garlic, sugar, fennel seeds, oregano, pimentón, and salt in a small saucepan over high heat. Bring the mixture to a boil, stir to dissolve the sugar and salt, and then turn off the heat.
Working with 1 leaf at a time, place the lettuce into a large bowl and pour a little of the hot brine on each leaf as you layer them in the bowl. Pour any extra brine into the bowl. Let the mixture cool to room temperature (at this point you can cover the bowl in plastic and refrigerate it for up to a day). Once the brine cools, drain the iceberg (save the brine for another use or discard) and pat dry the leaves with a kitchen towel.
While the lettuce is cooling down, stir together the olives, capers, and mayonnaise in a small bowl.
Divide the olive mixture between the tops and bottoms of each roll. Layer each sandwich evenly with provolone, peppers, pickled iceberg, and mozzarella. Close each sandwich and wrap each one tightly in plastic wrap.
Place a flat surface (like a cutting board or sheet pan) on top of the sandwiches and put something heavy on top (like a cast-iron skillet or a few cans of beans).
Cut each in half, and serve.