Chicken-Fried Chicken And Pickled Pepper Sandwiches

Ingredients

• 12 ounces small sweet peppers, such as baby bell peppers, cubanelles, or banana peppers
• 1 bay leaf
• 1 tablespoon plus 1 teaspoon brown mustard seeds
• 1 1/4 teaspoons whole black peppercorns
• 1 1/4 cups cider vinegar
• 1 cup water
• 1/3 cup granulated sugar
• 2 tablespoons plus 2 teaspoons kosher salt
• 1/2 cup buttermilk
• 1 cup all-purpose flour
• 1 tablespoon powdered sugar
• 1 teaspoon kosher salt, plus more as needed
• 1/2 teaspoon paprika
• 1/2 teaspoon freshly ground black pepper, plus more as needed
• 1/4 teaspoon baking powder
• 1/4 teaspoon ground mustard
• 2 (8- to 10-ounce) boneless, skinless chicken breasts
• 1 cup vegetable oil, for frying
• 1/2 cup mayonnaise
• 4 soft hoagie rolls, sliced in half horizontally
• 2 cups thinly sliced iceberg lettuce