4 thick lamb steaks or chops,
about 5 ounces each
3-4 tablespoons olive oil
1 sprig fresh thyme 3/4 cup lentilles de Puy
1 medium carrot 1/2 small head celeriac
1 medium leek
2 tablespoons coarsely chopped fresh parsley
1/4 cup Classic Vinaigrette
Sea salt and freshly ground black pepper
1 pound medium, slightly waxy
1 1/4 cups milk
1 1/4 cups heavy cream
1 clove garlic, sliced
1 sprig fresh thyme
1 bay leaf
3/4 cup grated Gruyere cheese
1 Remove the central bone from the chops. Trim off fat and neaten to nice "rump" shapes. Place in a bowl or plastic bag with half of the oil and the tips from the thyme sprig. Set aside to marinate in the fridge.
2 Cook the lentils in boiling salted water for about 15 minutes. Drain and season.
3 Cut the carrot, celeriac, and leek into 1/2-inch squares (we call this a brunoise). Heat the remaining oil in a saucepan and saute the vegetables until lightly browned, 5-7 minutes. Mix with the lentils and half the parsley, then bind with 2 tablespoons of the vinaigrette. Set aside.
4 For the gratin potatoes, preheat the oven to 400°. Peel the potatoes and slice thinly (use a mandoline or the slicing blade of a food processor). Bring the milk and cream to a boil with some sea salt, the garlic, and herbs, and simmer for a couple of minutes. Add the sliced potatoes and simmer for about 5 minutes until Just tender. Drain in a colander set over a bowl to catch the creamy milk.
5 Mix the potatoes gently with two-thirds of the cheese. Layer neatly into four medium ramekins or cocotte dishes, seasoning in between the layers. Spoon a little of the saved creamy milk on top of each ramekin and sprinkle with the last of the cheese. Place the ramekins on a baking sheet and bake for 8-10 minutes until the cheese Just turns a golden brown.
6 Meanwhile, heat a heavy-based non-stick frying pan until really hot. Remove the lamb steaks from the bowl or plastic bag, wiping off any thyme tips, and brown for 3-5 minutes on each side, seasoning lightly as they cook. The lamb should be served lightly pink- medium rare.
7 Reheat the lentils and spoon into the center of four plates. Place the lamb steaks on top (slice them first, if you like). Deglaze the frying pan with the last of the vinaigrette, stirring for a minute, then spoon these juices over the lamb. Sprinkle with the remaining parsley. Serve the gratin potatoes, still in their individual dishes, on the same plate. Simple and delicious!