Heat half the oil in a large non-stick frying pan over a medium-high heat. Add half the lamb. Cook for 3-4 minutes, turning until browned. Transfer to the removable bowl of a 5-6 litre capacity slow cooker. Repeat step with remaining oil and lamb.
Stir in tomato paste, Worcestershire sauce, honey and thyme.
Add lentils, stock cube, onions, carrots and parsnips. Pour over 3 cups hot water. Stir well. Cover with lid. Cook on high for 6 hours or low for 8 hours, or until lamb is tender.
Blend cornflour with 1 tablespoon water in a small bowl Remove lid from slow cooker. Stir in cornflour mixture. Cook uncovered on High for about 10 minutes, until thickened slightly.
Steam or microwave brussels sprouts until tender.
Serve lamb and lentils with sprouts and baguette.