1. Melt butter in a Dutch oven over medium-high heat. Add onion to pan; sauté 4 minutes. Add garlic; sauté 1 minute. Spoon onion mixture into a large bowl. Add half of lamb to pan; sauté 4 minutes or until browned. Remove from pan; add to onion mixture. Repeat procedure with remaining lamb.
2. Add wine to pan, scraping pan to loosen browned bits. Return lamb mixture to pan; add salt and pepper. Combine oregano, parsley, and rosemary. Add half of herb mixture to pan; bring to a boil. Cover, reduce heat, and simmer 1 1/2 hours or until lamb is tender. Add potatoes, turnips, and carrots to pan. Cover and cook 40 minutes or until tender. Add asparagus; cook 5 minutes or until asparagus is tender. Stir in remaining herb mixture.
Wine note: This succulent lamb shoulder surrounded by roasted root vegetables is fantastic with an earthy pinot noir. Try one that's rich and full bodied to mirror the richness of the lamb. Talley Pinot Noir 2006 from California's Arroyo Grande Valley ($36) is sensational. —Karen MacNeil