1. Heat the oven to 350° F. Bring a large pot of salted water to boil, add the macaroni, and boil until it’s just a shade under al dente (it will finish cooking in the oven). Strain the noodles and put them into a large mixing bowl.

2. Add the cheddar, Swiss, and Parmesan (save a small handful of the Parmesan for the top of the mac-n-cheese) to the bowl of pasta, and stir it all together until the cheese melts. Add the heavy cream and black pepper.

3. Bring another large pot of water to boil and add crab legs. Boil them until they are heated through, about 5-8 minutes, depending on their size. Remove them from the pot and set them aside until they are cool enough to handle.

4. Put a large sauté pan over medium-high heat and melt the butter. Add the onions and mushrooms, and sauté until they are soft, about 5 minutes. Add the liquid smoke and chicken stock, and stir to combine.

5. Use a serrated knife to cut open the crab legs and retrieve the meat, slice the meat into ½-inch round pieces, and stir them into the mac-n-cheese mixture.

6. Pour the crab mac-n-cheese into a baking pan, sprinkle the top with chives and the remaining Parmesan, and bake it uncovered for 30-35 minutes, until the top browns. Sprinkle the plated pasta with the lemon zest.