Coat slow-cooker bowl with nonstick cooking spray. Toss lamb with flour and place in bottom of slow cooker. Add potatoes, turnips, onion, carrots and celery, in that order.
Combine broth, wine, tomato paste, 1/2 tsp of the salt, 1/4 tsp of the pepper and the thyme. Pour over contents of slow cooker.
Cover and cook on HIGH for 6 hours or LOW for 8 hours. Stir in peas and remaining 1/2 tsp salt and 1/4 tsp pepper during last 15 minutes of cooking time. Serve with warm biscuits, if desired.
