- Bring lamb shoulder to room temperature. Pat dry with paper towels.
- Blitz onions, garlic and tomatoes in a blender. Pour into a bowl and add olive oil, mint, cumin, brown sugar, smoked paprika, salt and pepper. Mix well. Pour over lamb and marinate for a minimum of 30 minutes.
- Place lamb with marinade in a slow cooker on high heat. Add bouillon cube. Cook for 6-8 hours .
- Pre-heat oven to 190C. Prepare a medium sized roasting tray with aluminium foil. Place lamb on foil and fold foil up and over on all sides to prevent any liquid from leaking out.
- Pour out juice from slow cooker to a pan on medium-high heat and add remaining ingredients for BBQ sauce. Cook for 8-10 minutes until the sauce thickens.
- Pour half of the sauce to the lamb in foil and place tray in oven. Roast for 40 minutes and baste with sauce from the tray every 10 minutes.
- Let lamb rest for 10 minutes before carving.
- Serve with remaining sauce from the pan.
Serving ideas: Pulled lamb for tacos or sliders.