This recipe, excerpted from the cookbook Panini Express, does wonders for the familiar meaty hero sandwich just by pressing and grilling it. Warmed up, the deli ingredients just taste better. Of course, starting with the best-quality mortadellia, prosciutto, and provolone (look for versions imported from Italy) will also improve the quality of the sandwich. Use a thick, hearty baguette or Italian loaf to hold the generous filling,s and don't skip the peperoncini and peppery arugula, which cut the richness of the meats and cheese.
Heat a panini or sandwich press according to the manufacturer's instructions.
Slice the baguette pieces in half lengthwise with a serrated knife. Brush the insides with the oil and vinegar. Lay the bread, cut sides up, on a work surface. Arrange the arugula and then the peppers on the bottom halves. Drape the mortadella, prosciutto, and soppressata on top of the vegetables. Top with the provolone. Top each sandwich with the top half of each baguette.
Put the sandwiches on the press, pull the top down, and cook until they are browned and crisp and the cheese is melted, 5 to 7 minutes, depending on how hot your machine is. Carefully remove from the press and serve immediately.