Preheat the oven to 120 C or slow cooker to High.
Rub the lamb with a good tsp of sea salt, rosemary, pepper and thyme and shove the garlic into the cracks in the lamb (so they are nestled in). Place in the oven or slow cooker with 150ml of water at the bottom (1cm high to the bottom) for 6-7 hours until the lamb is falling off the bone.
While the lamb is cooking – make the salsa verde by blending the parsley, basil, olive oil, capers, vinegar and mustard. Blend until you have a smooth paste, and set aside.
Break the lettuce into individual leaves and place the peas at room temperature to defrost while the lamb is cooking.
When you take the lamb out add in the peas and butter lettuce to the lamb juice and stir through so they peas cook and the butter lettuce melt.
Serve with the salsa verde and some steamed greens
Images: Holly Clark Photography