Preheat the oven to 120C/250F/Gas ½.
For the herb crust, lay the ciabatta, lemon rind, capers, anchovies, onions and olives onto a baking sheet. Place into the oven for two hours to dry out.
Transfer the dried mixture to a food processor, add the parsley and basil and blend until fine breadcrumbs form. Spread the mixture onto a large plate or clean tray.
Turn the oven up to 180C/355F/Gas 4.
Season the lamb with salt and freshly ground black pepper.
Heat a frying pan until hot and add the olive oil. Add the lamb racks and fry on each side until browned.
Remove from the pan and brush the lamb racks with mustard so that they are completely covered and then roll them in the herb crust to completely coat.
Place the coated lamb racks into an ovenproof dish and transfer to the oven to bake for 12-14 minutes, until medium rare, or longer according to your taste. Turn the meat over halfway through. Remove from the oven and leave to rest.
For leeks and beans, heat a frying pan until hot, then add the butter and leeks. Gently fry the leeks for 4-5 minutes until softened, but not browned.
Add the beans and cook for a further 2-3 minutes.
Add the parsley and season, to taste, with salt and freshly ground black pepper.
For the red wine sauce, place the red wine into a shallow pan over a high heat and bring to the boil. Cook to reduce the wine by half, then add the chicken stock and continue boiling to reduce the liquid volume by half again.
Add the butter, season with salt and freshly ground black pepper.
To serve, place a spoonful of mashed potato onto each of four plates and place a spoonful of the leeks alongside. Slice the lamb in half and place on top of the leeks, then spoon the red wine sauce around.