Use a round boule bread loaf, and a small serrated knife and cut the boulle around the side evenly.
Rotate the loaf of bread, and cut the boule loaf in half removing the top from the bottom.
Use your fingers and scoop out the bread from the top and bottom of the boule.
Leave about a ½ inch rim around the top and bottom of the bread shells to allow the filling to be pressed flat inside the bread loaf and stay inside.
In a small bowl, mix the olives (or olive tapenade), pepperoncinis, parsley, olive oil, vinegar, capers, and black pepper. Spread 1 cup of the olive mixture on the bread bottom.
Next, layer all the sandwich ingredients: cheese, deli meats, spinach/lettuce spreads or toppings you like. Add the rest of the olive mixture if you have any left.
Place the bread tops of the boulle loaf back on, and press gently down. Use plastic wrap to tightly wrap the sandwich. Wrap sandwich tightly a couple times, and cover completely.
Place the sandwich between two baking sheets and weigh it down with some heavy objects like a large can, containers of juice, or a heavy skillet to press down the sandwich. The reason you want to do this is so it all holds together neatly in a "one hand" hold at the picnic!
Keep in the refrigerator at least couple of hours, overnight is better as it has time to press and the flavors are better the next day.
Use a serrated knife to cut the sandwich into 8 wedges.
Serve with side salads like easy pasta salad, macaroni salad and cut watermelon.