Ingredients

• 1/2 cup chicken stock or canned low-salt chicken broth
• 1/3 cup oyster sauce*
• 1/3 cup plum sauce*
• 1/4 cup mirin (sweet Japanese rice wine)*
• 1/4 cup orange juice
• 2 tablespoons chili-garlic sauce*
• 3 kaffir lime leaves**
• 1 tablespoon apple cider vinegar
• 1 tablespoon sugar
• 1 tablespoon oriental sesame oil
• 1 1/2 pounds pork tenderloin, cut into 12 rounds (each about 1 1/2 inches thick)
• 1/2 cup (about 4 ounces) roasted natural pistachios, finely chopped
• 2 tablespoons (1/4 stick) chilled unsalted butter, cut into 4 pieces
• Crispy Fried Leeks (optional)

Instructions

1. Combine chicken stock, oyster sauce, plum sauce, mirin, orange juice, chili-garlic sauce and kaffir lime leaves in heavy small saucepan over medium-high heat. Simmer until sauce is reduced to 1 cup, whisking occasionally, about 25 minutes. Whisk in apple cider vinegar and sugar. Remove from heat. (Sauce can be prepared 3 days ahead. Cover and refrigerate.) Remove lime leaves.
2. Preheat oven to 350°F. Heat sesame oil in heavy large skillet over high heat. Sprinkle pork with salt and pepper. Sauté pork until golden brown, about 1 minute per side. Transfer pork to work surface; brush each piece with sauce and dip in pistachios, turning to coat. Transfer pork to rimmed baking sheet. Bake until thermometer inserted into center registers 150°F, about 10 minutes.
3. Bring sauce to boil. Add butter one piece at a time, whisking just until melted before adding next piece. Transfer 2 pork medallions to each of 6 plates. Drizzle sauce around pork. Top with fried leeks, if desired. Serve immediately.
4. *Available at Asian markets and in the Asian foods section of many supermarkets. **Leaves of the kaffir lime tree; available frozen or sometimes fresh at Asian markets. If unavailable, substitute 2 tablespoons fresh lime juice and 1 teaspoon grated lime peel.
5. *Available at Asian markets and in the Asian foods section of many supermarkets.
6. **Leaves of the kaffir lime tree; available frozen or sometimes fresh at Asian markets. If unavailable, substitute 2 tablespoons fresh lime juice and 1 teaspoon grated lime peel.