Preheat the oven to 350°F. Grease a 9x13 casserole dish or baking dish and set aside.
Bring a large pot of water to a boil. Salt the water liberally. Boil the pasta until they are al dente, about 6 minutes. Drain, and rinse the pasta with cool water and set aside.
Combine all of the shredded cheese together and separate it into two bowls. About 1 ½ cups of the cheese will be layered between the pasta so set that portion aside.
In a medium-sized saucepan, combine milk, bay leaf, and clove. Allow the mixture to become steamy, do not boil.
In a large pot, melt the butter over medium heat. Once the butter has melted, add the unbleached flour and whisk it into the butter. Cook the roux for about 2 minutes to remove the raw flour taste, you do not want the roux to darken. Continue whisking.
Remove the bay leaf and clove from the milk and discard. Slowly ladle in the warm milk into the roux while constantly whisking. After a few ladles go ahead and slowly stream the milk into the roux, whisking constantly to prevent lumps. If lumps do form you can use an immersion blender to remove them.
Season the béchamel with the dashes of fish sauce (or Worcestershire sauce) and the seasonings. Simmer the béchamel sauce for at least 10 minutes, until the starchy flavor of the flour has been cooked out and the sauce has thickened to coat the back of a wooden spoon. Be sure to stir frequently.
Remove the pot from the burner and stir in the shredded cheeses. Taste the cheese sauce and adjust the salt and seasoning if necessary.
Stir the cooked pasta into the cheese sauce and add the crumbled chicken sausage. Stir until the pasta and sausage are fully coated with the cheese sauce.
Layer half of the pasta into the prepared baking dish and top it with half of the reserved shredded cheese. Spread the rest of the pasta on top of the shredded cheese. Sprinkle the remainder of the cheese on top of the macaroni.
In a small bowl, combine the panko crumbs, Parmesan, seasonings, and melted butter. Sprinkle the panko over the top layer of cheese. Bake the mac & cheese uncovered for 30 minutes or until the top is browned and bubbly. Allow it to cool for at least 5-10 minutes before serving.