Cut the rack of lamb in 1/2, just to the right of the 4th bone. Remove the outer layer of fat and the bones from the right sided rack so that when you are finished you just have the eye. In a hot saute pan sear the rack and eye in the olive oil until well-browned on all sides. Remove the eye from the pan. Put the rack in the oven for 5 to 6 minutes or until rare, then put on stovetop. Return the boneless rack (eye) to the pan and add garlic, thyme and butter. Baste for 2 minutes over low heat then remove both and let rest on a cooling rack.
For the gateau: Starting in salted cold water, cook the potatoes until tender. Drain the potatoes and fork crush them with the butter. Season with salt and pepper. Fill two greased ring molds (2 1/2-inches in diameter by 1 1/2-inches in height) 3/4 of the way with the potatoes and form a well. Put the goat cheese in the center and cover with the potatoes. Smooth the top.
For the fricassee: Render the bacon over low heat. When bacon is lightly crisp, strain through a chinois. In a small saucepan, sweat the onions and butter. Season with salt and pepper. Add the peas, bacon and Garlic Puree. If the mixture is dry, you may add a few drops of water. Season to taste.
Assembly: Warm the potato gateaus until warm in the center, about 5 minutes. Lift off the rings and put in the center of the plate. Cut the rack into 4 chops and the eye into 4 slices. Lean two chops and two slices on the gateau. Divide the peas into two portions and spoon onto the plate. Sauce over the top with warm lamb jus.;
Bring the garlic to a boil, starting with cold water. When water reaches a boil, strain garlic and refresh under gently running cold water. Repeat process 6 to 8 times until garlic is tender and mild flavored. Puree in food processor and pass through chinois.
This recipe will make more than you need, but may be frozen for use at a later date.