Peel off the roasts' layer of fell (membrane) and fat, if present, down to silver skin. Place the lamb in a large sealable plastic bag in a shallow baking dish. Add wine, 1 clove garlic and nutmeg. Seal the bag. Marinate in the refrigerator for 4 to 24 hours, turning bag occasionally.
Heat 1 tablespoon each oil and butter in a medium skillet over medium heat. Add rosemary and the remaining 1 clove garlic; cook 1 minute. Add breadcrumbs; cook and stir 3 minutes. Remove from heat and add cranberries, lavender, salt and pepper. Stir in the remaining 2 tablespoons oil.
Preheat oven to 450°F. Remove the lamb from the marinade, reserving marinade. Place the lamb, bone-side down, in a shallow roasting pan lined with foil. Pat the crumb mixture evenly over the lamb. Pour the reserved marinade into the roasting pan.
Roast, uncovered, for 25 to 30 minutes or until an instant-read thermometer registers 140°F (medium-rare) or 155°F (medium). To prevent overbrowning, cover loosely with foil for the last 5 minutes of roasting. Let stand for 15 minutes.
Tip: Look for dried lavender at natural-foods stores or check www.deandeluca.com.