Crush the Juniper berries, cloves and black pepper in a mortar and pestle. Place all the brine ingredients in a heavy-based saucepan filled with 4L of water and bring to the boil over high heat. Remove from the heat, strain through a fine-meshed sieve and store in the fridge. Do not use until cooled completely.
Salsa Verde
Place the lamb in a container, skin side up and pour over enough brine to cover, (don'r worry of the brine doesn't completely cover the lamb, leaving the skin exposed is fine). Then cover with plastic film and place in the fridge for 3 hours to lightly brine. Don't leave it any longer than this you don't want to overpower the lamb, this just adds a unique flavour its not to tenderise as other brines may do.
In a food processor, pulse the anchovies with the capers and garlic until a fine paste forms. Add the olive oil, vinegar and mustard and pulse to combine. Add the herbs and pulse until finely chopped. Check for seasoning - Add a little more salt, pepper or red wine vinegar as required and pulse to mix. Transfer to a jar, seal and set aside.
Note - This keeps well in the fridge - So don't be afraid to make a double batch!