Step 1

Prepare the following, adding each to the same medium bowl as you complete it: Finely chop 1/3 cup large pimento-stuffed olives. Pit and finely chop 1/3 cup pitted black olives. Finely chop 1/3 cup giardiniera, 1/4 cup marinated roasted red peppers, and 1 garlic clove.

Step 2

Add 1/4 cup extra-virgin olive oil, 1 1/2 teaspoons red wine vinegar, 1 teaspoon capers, 1/2 teaspoon black pepper, and 1/2 teaspoon celery salt. Stir to combine, then cover and refrigerate for at least 1 hour or up to 1 week.

Step 3

Split 1 bread loaf in half horizontally with a serrated knife. Place the two halves cut side-up up on a work surface. If each half is taller than 1 1/2 inches, hollow out the insides of the bread by pulling out some of the soft interior.

Step 4

Spoon half of the olive salad and its oils evenly onto the bottom half of the loaf. Layer on the meats and cheese in the following order: half of the mozzarella slices (2 ounces), 4 ounces thinly sliced salami, half of the provolone slices (2 ounces), 4 ounces thinly sliced mortadella, the remaining mozzarella, 4 ounces thinly sliced capicola, and the remaining provolone.

Step 5

Use the back of a spoon to press on the remaining olive salad, then pour off the oil into a small bowl. Spoon the olive salad evenly on top of the provolone. Drizzle the cut side of the top bread slice with the reserved olive salad oil. Close the sandwich with the top half of the bread.

Step 6

Wrap the entire sandwich tightly in aluminum foil. Weight it down with a heavy object, such as a large Dutch oven or bricks, to compress the sandwich. Let sit at room temperature for 1 to 3 hours.

Step 7

Toast the sandwich if desired: Arrange a rack in the middle of the oven and heat the oven to 375ºF. Place the foil-wrapped muffuletta directly on the rack and bake until the bread feels crisp and toasted, 10 to 20 minutes.

Step 8

Unwrap the sandwich and place on a cutting board. Cut into triangles with a serrated knife and serve with pickled pepperoncini or potato chips if desired.