Eggplant and Country Ham Ragù

Name: Eggplant and Country Ham Ragù
Ingredients: 8 tablespoons olive oil, divided; 1½ pounds globe eggplants (about 2 small), cut into ½-inch pieces; Kosher salt, freshly ground pepper; 12 slices thin country ham or prosciutto (about 3 ounces); 1 small onion, finely chopped; 2 garlic cloves, finely chopped; 1–2 canned chipotle chiles in adobo, finely chopped; 1 tablespoon unsweetened cocoa powder; 1 tablespoon tomato paste; ½ cup store-bought tomato sauce; 1 tablespoon fish sauce (such as nam pla or nuoc nam); 12 ounces linguine or spaghetti; 2 tablespoons unsalted butter; 1½ ounces Parmesan, finely grated (about ½ cup); 3 tablespoons finely chopped fresh parsley