Ingredients

• 2 tablespoons (1/4 stick) butter, divided
• 2 tablespoons olive oil, divided
• 2 cups chopped leeks (white and pale green parts only; about 2 medium)
• 1 cup low-salt chicken broth
• 1/2 cup dry white wine
• 2 garlic cloves, minced
• 1/2 cup crème fraîche or sour cream
• 3 tablespoons whole grain Dijon mustard
• 2 1-pound pork tenderloins, each cut crosswise into 6 slices
• 2 tablespoons chopped fresh chives
• 1 tablespoon chopped fresh tarragon
• 2 tablespoons chopped fresh parsley

Instructions

1. Melt 1 tablespoon butter with 1 tablespoon oil in large skillet over medium-high heat. Add leeks and cook until beginning to turn golden, stirring frequently, about 5 minutes. Stir in broth, wine, and garlic. Boil until mixture is reduced to 1 2/3 cups, about 4 minutes. Whisk in crème fraîche and mustard; set aside. (Sauce can be made 2 hours ahead. Let stand at room temperature.) Melt 1 tablespoon butter with 1 tablespoon oil in another large skillet over medium-high heat. Sprinkle pork with salt and pepper. Sauté until browned and cooked, about 5 minutes per side. Transfer pork to platter. Add sauce to skillet; simmer sauce over medium heat until slightly thickened, scraping up any browned bits, about 2 minutes. Stir in chopped chives and tarragon. Season with salt and pepper.
2. Return pork to skillet. Cook over medium heat just until rewarmed, stirring frequently, about 1 minute. Transfer to platter, sprinkle with parsley, and serve.