Cut fat and tendons from the racks of lamb. Important: remove the tendons from between the individual ribs, then cut the rack in half, rub well with garlic and season with salt and pepper. Brown in a pan with hot groundnut oil. Cut the herb crust mixture (recipe below) into slices and lay on the racks of lamb. Place in an oven preheated to 220 degrees for about 3 minutes. Remove racks of lamb from oven and allow to rest. Dice vegetables, fry gently in olive oil with a little finely chopped onion and garlic, add tomato purée and season to taste.  Put racks of lamb back in the oven for about 3 minutes until pink. At the same time, heat the juices from the lamb, put a portion of ratatouille on each plate, pour the lamb jus around it and place the rack of lamb on top. Best accompaniment: potato gratin.

Allow butter to soften to room temperature, and put in a small mixing bowl along with the flour or breadcrumbs. Chop fresh herbs roughly, remove stalks from thyme and rosemary and chop finely and add to the bowl. Season with salt and pepper, and blend to produce a smooth, green mixture. Taste and adjust seasoning.  Place the mixture on a sheet of cling film, roll into a sausage and seal. Cool in fridge for 2 to 3 hours. For the rack of lamb, cut into slices 2 to 3 cm thick.