1 pound cavatappi or elbow pasta (I used penne)
2 tablespoons extra-virgin olive oil
6 tablespoons butter
3 ribs celery, finely chopped
1 medium onion, finely chopped
1/2 small red bell pepper, seeded and finely chopped
3 to 4 cloves garlic, finely chopped
1 bay leaf
About 2 tablespoons freshly chopped thyme leaves, several sprigs (I used 1/2T dried)
About 1 tablespoon grated lemon zest (I used 1T lemon juice)
Freshly ground black pepper
3/4 pound fresh lump crabmeat, picked for shells and flaked
1 tablespoon Old Bay seafood seasoning (I used cajun seasoning)
3 tablespoons all-purpose flour
2 1/2 cups milk
Freshly grated nutmeg, to taste (I left this out)
1 tablespoon Dijon mustard (I left this out)
1/3 pound, about 1 rounded cup grated sharp white Cheddar
1/3 pound, about 1 rounded cup shredded Gruyere or Swiss cheese (I used monterey jack)
3 tablespoons hot sauce (recommended: Frank's Red Hot)
1 cup panko bread crumbs
A generous handful flat-leaf parsley, finely chopped
1/2 cup grated Parmigiano-Reggiano cheese, a couple of handfuls
Bring a large pot of water to a boil over medium heat, then salt the water. Add the pasta and cook for 3 to 4 minutes, (it will be undercooked). Cool, drain well and add it to a large bowl.
Meanwhile, in a medium saucepan, heat 2 tablespoons of extra-virgin olive oil, 2 turns of the pan, and 1 tablespoon of the butter over medium to medium-high heat. Add the celery, onion, red pepper, garlic, bay leaf, thyme, lemon zest, salt and pepper, to taste. Cook to tender, 6 to 8 minutes. Add the crabmeat to the vegetables and season liberally with seafood seasoning. Stir to combine, then remove from heat.
In a medium sauce pot, over low heat, melt 3 tablespoons butter and whisk in the flour. Cook for 1 minute, then whisk in the milk and bring to a bubble. Season the sauce with salt, pepper and nutmeg, to taste, and cook for a few minutes, until the mixture coats the back of a spoon. Add the mustard and the cheese and stir in a figure 8 motion. Add the vegetables and crab, sauce to the bowl with the pasta and transfer the mixture to individual baking crocks or a large casserole dish. This can be made ahead to this point and refrigerated.
Preheat the oven to 375 degrees F.
To complete the dish, melt a couple of tablespoons butter in a small skillet, over low heat and add 3 tablespoons hot sauce. Warm through, then add the panko crumbs and toss to evenly coat the crumbs in sauce mixture. Cool the crumbs, then toss in the parsley and 1/2 cup grated Parmigiano -Reggiano cheese. Top the mac n cheese with the spicy crumb mixture. Arrange individual crocks on a baking sheet or put the casserole on baking sheet to catch any drips. Bake until brown and heated through, about 10 minutes. If cooking from cold, the mac n cheese will take 40 to 45 minutes, but add the crumbs the last 10 minutes of baking.