To make the lamb ribs, preheat the oven to 140C/120C Fan/Gas 1. Place the ribs, bay leaf, rosemary and garlic in a roasting tin and cover with the oil until they are completely submerged. Cook for 3 hours and leave to cool in the fat.
When ready to cook, remove the ribs from the fat, wipe off the excess oil and cut into individual ribs.Fry in a frying pan over a medium heat until crisp and golden. Season with salt and pepper.
To make the shallot purée, heat the butter in a frying pan and fry the shallots gently over a very low heat for 20–30 minutes. Place in a food processor or blender and blitz to a purée with the cream.
To make the roast shallots, preheat the oven to 200C/180C Fan/Gas 6. Heat the oil in a frying pan and fry the shallots, cut-side down until golden. Add the butter, garlic and thyme and cook for another few minutes. Transfer to a baking tray and roast for 15–20 minutes, or until softened.
For the crumbs, heat the olive oil in a saucepan over a high heat. Add the anchovies, garlic and cumin seeds and fry for a minute. Add the crumbs and fry until golden. Remove the mixture with a slotted spoon and drain on kitchen paper. Leave to cool slightly and then sprinkle with the paprika, parsley and mint.
To serve, spoon the shallot purée onto warmed plates and top with the roast shallots and lamb ribs. Scatter over the crumbs and garnish with watercress.