Add shrimp and lobster to vacuum bag and sous vide for 6 hours at 130 degrees Fahrenheit.

Melt butter in large pan. Add flour and cook for a minute. Add garlic, sherry, stock cubes, lemon juice, cream and spices and whisk together (it will be quite thick). Add lobster base. Add shellfish and the liquid in the sous vide bag to the sauce and stir. Add cooked pasta and stir, cooking a few minutes until all is very warm.

Alternately to sous vide: you can steam the shellfish until it is cooked and add to the sauce as above but I highly recommend sous vide for the shellfish because it gives more of a lobster flavor to all of the meat, and keeps the meat very tender, even after cooking with the sauce.