In a small bowl, stir together the mayo, yellow mustard and grainy mustard until well combined.
Rub the outer side of the top and bottom of each roll with 1 tablespoon of the softened butter and arrange, butter-side down, on a cutting board. Spread the mustard mixture on the inside of each piece of bread.
On the bottom half of each piece of bread, layer 2 slices of Swiss cheese, followed by 2 slices of ham, a layer of Cuban-Inspired pulled pork, a drizzle of the mojo sauce, a few slices of pickles, and then 2 more slices of Swiss on top. Close with the top half of the bread. Repeat with the second loaf and fixings.
Heat up a panini maker according to the directions. Then, working in batches, press the sandwiches until golden brown and the cheese has melted, 5 to 6 minutes. Transfer to a board and cut each one in half on a bias, then serve.
Notes
If you do not have a panini maker, place this into a skillet with a heavy skillet on top of the sandwiches to press them down for a good sear, about 3 minutes per side.