Trim fat from lamb. Make lengthwise slits halfway through lamb. Insert a garlic slice into each slit. Arrange bacon slices in a crisscross pattern over lamb.
Combine orange marmalade, French dressing, and lemon juice in a small saucepan. Bring to a boil over medium heat, stirring occasionally. Remove from heat, and set aside.
Place lamb on a rack in a roasting pan. Insert meat thermometer into thickest part of roast, if desired. Brush lamb with marmalade mixture. Bake, uncovered, at 325° for 1 hour and 45 minutes or until meat thermometer registers 140° (rare) to 160° (medium), basting occasionally with marmalade mixture. Transfer lamb to a serving platter. Let stand 15 minutes.
Beat butter and honey at medium speed of an electric mixer until smooth. Stir in hazelnuts and bourbon. Serve butter mixture with lamb. If desired, garnish with chive blossoms, mint, oregano, thyme, and vegetables.