We have enjoyed this sandwich many times throughout the years. I think it's the olive tapenade that wins us over time and time again. It's from one of our favorite cookbooks, Complete Outdoor Living Cookbook from Williams-Sonoma.
2 large red bell peppers
1 round loaf sourdough or coarse country bread
1 can (6 oz/185g) pitted black olives, drained
1 clove garlic
2 tablespoons olive oil
1/2 lb thinly sliced baked ham or prosciutto
1 large ripe tomato, thinly sliced
1 cup packed fresh basil leaves or 4-6 leaves of red leaf lettuce
Preheat the broiler. Cut the bell peppers into quarters and remove the stems, seeds, and ribs. Place the quarters, cut sides down, on a baking sheet and broil about 4 inches below the heat unti the skins blacken and blister. Transfer to a paper bag and seal; let steam until cool enough to handle. Peel off and discard the skins. Set the peppers aside.
Place the bread on a cutting board and, with the tip of a serrated knife, cut a large circle in the top about 1/2 inch deep and 1 inch from the edge. Pull out the circle of crust; remove all the bread attached to it to make a lid. Pull out all the bread from the interior of the loaf, leaving a shell 1/2 inch thick. Set the bread shell and lid aside. (Reserve the pulled-out bread for another use)
In a blender or food processor, combine the olives, garlic, and olive oil; process until fairly smooth. Using a rubber spatula, spread the olive paste around the inside of the bread shell and on the underside of the bread lid. (Alternatively, mince the olives and garlic, place in a small bowl and stir in the olive oil to make a coarse paste. Spread the olive paste on the bottom of the bread shell.) Line the bread shell with half of the ham or prosciutto. Top with half of the roasted red pepper quarters, then half of the tomato slices, and a few basil leaves or 2 or 3 lettuce leaves. Use just enough to cover the filling without overlapping too much.
Repeat the layers, ending with basil or lettuce. Replace the bread lid and press down lightly to compact the layers. Cut into layers and serve.