Michael Natkins Kouftikes de Prasa Sandwiches

Name: Michael Natkin's Kouftikes de Prasa Sandwiches
Ingredients: For the Spicy Cabbage:; 2 cups finely shredded red cabbage; 1⁄2 teaspoon kosher salt; 1⁄4 cup white vinegar; Half a preserved lemon, finely chopped; 2 teaspoons harissa or Thai-style chile sauce (such as sriracha); For the Leek Patties:; 2 large leeks, white and light green parts only (about 12 ounces); 2 tablespoons extra-virgin olive oil; 3⁄4 teaspoon kosher salt; 4 large eggs, beaten; 1⁄2 cup bread crumbs (preferably homemade); 1⁄2 teaspoon ground cumin; 1⁄4 teaspoon Aleppo pepper or cayenne; Pinch of ground cinnamon; Vegetable oil, for shallow frying; Flaky sea salt (such as Maldon); To finish the sandwiches:; 4 pita breads, lightly toasted or grilled; 20 thin half-moons of cucumber; 1⁄2 cup thick Greek yogurt or labneh; Ground sumac; A handful fresh mint or cilantro leaves, torn