To make olive salad: Lightly crush olives on wooden cutting board with the heel of your hand. Break up any large pieces of vegetables in giardiniera. Combine all ingredients in a large bowl with a resealable lid, making sure everything is immersed in olive oil. Stir, cover container tightly, and refridgerate at least 2 days (pref 1 week).
To make sandwich: Half loaf of bread lengthwise. Spoon olive salad to one side. Spread olives out, breaking them into pieces with your hands and pushing into bread. Coat other side with oil.
Layer olive-salad-laden side of bread with overlapping slices ham, mortadella, provelone, and swiss. Top with oil-coated side. Cut loaf into 4 wedges;
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