Ingredients

• 6 tablespoons (3/4 stick) butter, room temperature
• 3 tablespoons fennel seeds, crushed in plastic bag with mallet
• 3 large garlic cloves, minced
• 2 tablespoons Dijon mustard
• 1 1/2 tablespoons soy sauce
• 1 tablespoon coarsely ground black pepper
• 1 1/2 teaspoons dried crushed rosemary
• 2 tablespoons olive oil
• 1 6- to 6 1/2-pound bone-in leg of lamb, well trimmed
• 2 cups dry red wine
• 1 1/3 cups low-salt chicken broth
• Fresh rosemary sprigs (optional)

Instructions

1. Mix all ingredients with fork in medium bowl. (Can be made 1 day ahead. Cover and refrigerate. Bring to room temperature before using.)
2. Position rack in bottom third of oven and preheat to 450°F. Pour 2 tablespoons oil into large roasting pan. Place pan directly atop 2 burners over medium-high heat. Sprinkle lamb with salt and pepper. Add lamb to pan and brown on all sides, about 8 minutes total. Remove pan from heat. Brush lamb with half of seasoned butter.
3. Roast lamb 30 minutes. Reduce heat to 350°F; continue roasting until thermometer inserted into thickest part of meat registers 130°F for medium-rare, about 40 minutes longer. Transfer to platter; tent with foil. Let stand 20 minutes.
4. Skim off fat from drippings in roasting pan. Place pan atop 2 burners over high heat. Add wine and broth. Boil until mixture is reduced to 2 cups, about 13 minutes. Whisk in remaining seasoned butter (sauce will be thin). Season sauce to taste with salt and pepper.
5. Garnish lamb with rosemary sprigs, if desired. Serve with sauce.