Bring a pot of water to boiling for the pasta. Saute lobster meat in oil until it is no longer translucent, and set aside. Cook the pasta until al dente and drain well so that you don't have excess cooking water which will dilute the flavor. While the pasta is cooking, melt butter in a large saucepan over medium heat, and add the onion and garlic, cooking until translucent, being careful not to burn it. Add the flour a little at a time to make a roux. Do this gradually because some batches of flour absorb more than others and you may not need as much. Add the bay leaves, and then incorporate the vegetable or fish stock a little at a time to form a smooth sauce. Simmer for a least 10 minutes to allow the flour to "cook out," then remove the bay leaves. Add the heavy cream and Cheddar, then season with salt and white pepper. Stir the lobster meat into the cheese mixture, then fold in as much pasta as you need to acquire the right consistency for macaroni and cheese. Transfer to a serving bowl and drizzle sparingly with truffle oil and garnish with chopped chives.
Recipe courtesy "Robert, the First," by Robert Irvine with Brian O'Reilly, Harper Collins Publishers, 2006