Pork Medallions with Balsamic-Shallot Sauce

Ingredients:

• 1 (1-pound) pork tenderloin, trimmed
• 1/2 teaspoon salt
• 1/2 teaspoon dried thyme
• 1/8 teaspoon black pepper
• 1/8 teaspoon ground allspice
• Cooking spray
• 1/4 cup finely chopped shallots
• 1 teaspoon butter
• 1 tablespoon brown sugar
• 3 tablespoons balsamic vinegar

Source