4 large pork medallions 1/2 teaspoon salt 1/2 teaspoon coarse ground black pepper 1 Tablespoon olive oil 12 small boiling onions, peeled and trimmed One 3" piece of vanilla bean, split lengthwise and scraped 3/4 cup madeira wine 2 Tablespoons balsamic vinegar 2 teaspoons corn starch
Season pork with salt and pepper.
Heat oil in a large skillet over medium-high heat. Add pork and onions; cook for 4 minutes on each side, until nicely browned. Add vanilla scrapings, vanilla bean and wine to pan, scraping to loosen browned bits. Cover, reduce heat and simmer 20 minutes. Remove pork and onions from pan and tent with foil.
In a boel combine balsamic vinegar and cornstarch and add to wine mixture in pan; bring to a boil. Cook for 1 minute, stirring constantly. Discard vanilla bean.