Allow at least 2 hours for the lamb stock and confit tomatoes, two steps that can be done in advance.

Cooking time for the lamb: 10 minutes

Lamb stock

1. Bone the two racks to obtain two cylinders of meat. Sauté the bones and trimmings in very hot oil.
2. When the bones are well browned, add the finely diced carrot, onion and leek.
3. Add the white wine and stir with a wooden spoon to deglaze the caramelized juices, then add the water. Reduce, add the tomato and reduce again to obtain a good lamb stock.

Confit tomatoes

1. Prepare the confit tomatoes: blanch, peel and seed the tomatoes.
2. Place the tomato wedges sprinkled with thyme and olive oil on a baking sheet in a 100° C (215° F) oven for 2 hours.

Onion compote

1. Slice the onions and place them over the heat with 2 anchovies and 1/2 tsp. honey. Cook gently for 45 minutes.

Cooking the lamb and finishing

1. With a larding needle, insert 4 anchovies per rack into the meat.
2. Sear the lamb in a skillet for 1 minute on each side for rare, or a little longer for medium-rare. Let cool.
3. Place a layer of onions and confit tomatoes on the meat.
4. Wrap up in puff pastry; decorate the top, brush with egg yolk and roast in a 250° C (500° F) oven for about 10 minutes.
5. Serve with the lamb jus, well flavored with thyme.