I assumed it was Italian in origin, but apparently it first made it's appearance in an Italian grocery in New Orleans.
I don't think I've ever had all the ingredients for the olive salad when I've made this, but it still works. The olives, parsley, garlic, and olive oil are the most key components. I've also used a variety of deli meats in place of the ones listed here - try salami, ham, and bologna as more-common substitutes.
Lastly, good bread is vital. You can make your own using the easy baguette recipe and shaping it into a ball for a round loaf. Bake at 350 for 25 minutes. I sliced off the top of the bread because it formed a huge peak which would have made this already-huge sandwich very hard to fit into my mouth.
from Whole Foods
Let this sandwich sit for several hours for the flavors to meld and the oil to impart the bread with a delicious flavor.
1 1/2 cups chopped pimiento-stuffed green olives
1 cup chopped black olives
2/3 cup extra virgin olive oil
1 tablespoon prepared horseradish
5 tablespoons chopped parsley
1/2 cup chopped pimiento peppers
2 anchovy fillets, mashed (optional)
1 tablespoon finely chopped garlic
1 teaspoon dried oregano
2 teaspoons lemon juice
1 (8- to 10-inch) round loaf crusty Italian bread or large baguette
Shredded lettuce (optional)
Thinly sliced tomatoes (optional)
1/4 pound thinly sliced mortadella or bologna
1/4 pound thinly sliced smoked provolone or fresh mozzarella
1/4 pound thinly sliced ham
1/4 pound thinly sliced sopprasetta or salami
Mix olives, oil, horseradish, parsley, pimiento peppers, anchovies, garlic, oregano, lemon juice and pepper in a glass or ceramic bowl to make an olive spread. Cover and refrigerate for 8 hours, or overnight.
Cut bread in half horizontally and pull out some of the soft interior. Drain olive spread and reserve the liquid. Brush both sides of the bread generously with the reserved liquid, then place half of the olive spread in the hollow of one piece of the bread. Arrange a layer of lettuce and tomatoes on top, then continue with a layer of mortadella, provolone, ham and sopprasetta, alternating ingredients until you have used them all. Finally, top with remaining olive salad and cover with the other half of the bread.
Wrap the loaf tightly in plastic wrap and arrange on a large plate. Cover with a small plate and weigh down with several pounds of canned goods or a cast-iron skillet. Refrigerate for at least 30 minutes, then cut into wedges and serve.