3 tablespoons extra-virgin olive oil
1 cup diced red onion
12 ounces boneless pork loin, cut into 1/2-inch cubes 1 teaspoon freshly grated orange zest, plus
6 strips for garnish
1/4 cup good-quality balsamic vinegar
1 potato, diced into ½-inch cubes and cooked until tender
3 tablespoons water
Sea salt and freshly ground black pepper
Fresh Pasta Dough, rolled and cut into 5-inch squares with a fluted pastry wheel
1 egg, beaten, with 1 teaspoon water for egg wash
6 tablespoons mostarda
To make the filling: Heat the olive oil in a medium sautè pan over medium heat. Add the onion and cook until softened, but not browned. Add the pork and orange zest and cook for 6 to 8 minutes longer, until browned. Deglaze the pan with the balsamic vinegar, stirring to loosen any browned bits from the pan. Add the potatoes and water and cook until reduced, about 3 to 4 minutes. Season with salt and pepper; remove from the heat.
To assemble the ravioli: Place 2 heaping tablespoons of the cooled filling on 6 of the pasta squares. Brush the edges with egg wash and top with another pasta square, pressing the edges firmly to seal.
In a large pot of salted boiling water, cook the ravioli for 3 to 4 minutes, until al dente. Drain and place on individual serving plates. With a very sharp knife, make a slit in the top to expose the filling. Top with a tablespoon of mostarda, garnish with an orange strip, and serve at once.