1 pound uncooked large shell macaroni
10 tablespoons Cabot Salted Butter, divided
¾ cup Panko breadcrumbs
½ cup King Arthur Unbleached All-Purpose Flour
½ teaspoon grated nutmeg
3 cups half-and-half
8 ounces Cabot Horseradish Cheddar, grated (about 2 cups)
4 (1-ounce) Cabot Swiss Slices, broken into small pieces
2 (6-ounce) cans lump crabmeat, drained and broken up
2 tablespoons Cabot Salted Butter, melted
COOK macaroni shells in large pot of boiling salted water according to package directions; drain well and set aside.
PREHEAT oven to 350ºF. Butter 8-by-8-inch baking dish.
MELT 2 tablespoons of butter in large heavy saucepan over medium-low heat; pour into small bowl. Add breadcrumbs, stir to combine and set aside.
ADD remaining 8 tablespoons butter to saucepan. When melted, stir in flour and nutmeg. Cook, stirring, until bubbly and frothy; remove from heat.
SLOWLY whisk in half-and-half until smooth. Return to heat and stir in cheddar and Swiss cheeses. Cook, stirring, until cheese is melted and sauce is thickened and creamy. Stir in crabmeat and reserved macaroni.
POUR mixture into prepared dish, then sprinkle with reserved crumbs. Bake for 15 to 25 minutes or until golden on top and bubbly on edges.