Start by slicing the ciabatta loaf in half horizontally. Place the two halves on a parchment-lined baking sheet, cut side up.

In a mason jar, combine olive oil, balsamic vinegar, red wine vinegar, dried oregano, minced garlic, chopped parsley, and a pinch of salt and pepper. Seal and shake until well-blended.

Drizzle a generous amount of oil mixture over one half of the ciabatta. Layer basil and arugula on the other half, then spread olive salad and stack cheeses, meats, and tomatoes on the bottom half.

Close the sandwich halves, wrap tightly in plastic wrap, and place a heavy object on top. Refrigerate for at least 8 hours.

When ready to serve, unwrap, wrap in parchment paper, slice into portions, and secure with twine.