In a small pan, melt 2 tablespoons of butter over medium heat.
Pour panko bread crumbs into a medium sized bowl and add butter. Stir until panko is slightly wet and set aside.
Fill a 2-quart saucepan with water, boil and add a pinch of salt and macaroni. Cook until very al dente (about a minute less than the recommended cooking time on the package). Rinse macaroni with very cold water and set aside.
In a small saucepan, heat 1 tablespoon of butter until melted. Add shallot and sauté until translucent and soft, about 6 minutes. Set aside.
In a large saucepan, melt remaining 6 tablespoons of butter until bubbling. Add flour and cook, stirring constantly for about a minute.
Pour hot milk into saucepan with butter and flour mixture, in parts, whisking constantly until well combined and there are no lumps. Continue cooking, whisking constantly, until mixture becomes thick and begins to bubble.
Remove from heat and add Old Bay, pepper, salt, allspice and cayenne. Whisk until thoroughly combined. Taste for additional seasoning.
Add prepared shallots, 1 1/2 cups of Gruyère, 1 1/2 cups of aged cheddar and 1 1/2 cups of the sharp cheddar to the mixture. Set cheese sauce aside.
In a very large bowl, combine cheese sauce and cooked, cooled macaroni. Pour mixture into a large pan or casserole dish.
Cover casserole dish with remaining cheese. Sprinkle the top with wet panko.
Bake at 375 degrees for about 30 minutes—or until crust becomes golden.
While macaroni and cheese is in the oven, heat two tablespoons of butter over medium heat.
When butter begins to bubble, add crab, green onion and 2 tablespoons of Old Bay Seasoning. Sauté over medium heat, stirring frequently, for 4-5 minutes. Set aside.
When macaroni and cheese is cooked, set aside to rest for 5-10 minutes. Spoon over crab mixture and serve immediately.
What happens when chefs read the bad reviews written about them from around the web and beyond? We turned on the camera to find out.
This episode: Chef Chris Beerman of Citizen's Band in San Francisco.