Mix the cheese, nuts, shallots and thyme. Preheat oven to 325°F. In a pan, heat the olive oil. Add salt and pepper, then brown the racks of lamb on all sides and ends. Cook in the oven for one hour, or until the internal temperature reaches 160 °F. Spread the cheese and nut mix on the surface of the racks, and broil until brown. Serve with mashed potatoes and green vegetables. You can also replace the blue cheese with goats’ cheese, and the walnuts with hazelnuts.