3 1/2 pounds pork shoulder, trimmed and butterflied
1 1/2 teaspoons salt
1 teaspoon freshly ground black pepper
1 tablespoon dry mustard
1 tablespoon honey
2 tablespoons plus 1/2 teaspoon vegetable oil
1/2 teaspoon water
2 tablespoons caraway seeds
10 tablespoons (1 stick plus 2 tablespoons) unsalted butter, cold
6 tablespoons minced shallots
3/4 cup red wine vinegar
3/4 cup brown veal stock or chicken stock
1/2 cup heavy cream
Salt and freshly ground black pepper, to taste
Preheat oven to 400 degrees F. Lay meat flat on counter and using a sharp knife, make several slits about 1/4-inch deep by 1-inch long. Sprinkle with salt and pepper.
In a small bowl, make a paste with mustard, honey, 1/2 teaspoon oil, and water. Spread mixture evenly over meat then cover with caraway seeds. Press seasonings into slashes with your fingers to infuse meat with flavor. Roll meat, along the length, to enclose stuffing and tie with string at 1-inch intervals. Season outside with salt and pepper.
Heat remaining 2 tablespoons oil in a large skillet over high heat. Cook meat until brown all over then transfer to a rack in roasting pan. Bake, uncovered, 45 minutes, or until juices run clear when pierced with a sharp knife.
Just before serving, make sauce. Melt 4 tablespoons of the butter in a medium skillet over moderate heat. Sauté shallots until golden. Add vinegar, turn heat to high and reduce by half. Add stock and reduce again by half. Add cream, bring to a boil, and add remaining butter, in small pieces, whisking constantly until smooth. Adjust seasonings with salt and pepper.
Remove strings from pork and slice thinly across the roll. Arrange slices on serving plates, top with sauce, and serve immediately.