Preheat the oven to 200ºC. Sprinkle salt over both sides of the lamb, drizzle 1 Tbsp of oil over the top. Cook to your liking.
To prepare polenta, bring 2 ½ cups water to a simmer. Gradually add polenta, stirring constantly with a whisk. Cook 3 minutes or until thick, stirring constantly. Add salt to taste.
Warm the Black Truffle Sauce with the remaining oil over low heat.
Serve the lamb on a bed of polenta and drizzle the warmed Black Truffle Sauce over the top.