Four-Cheese Macaroni and Cheese

Ingredients:
kosher salt, to taste
8 oz hollow pasta
3 slices crustless white bread
6 Tbsp unsalted butter
1/2 tsp paprika
3 sprigs fresh thyme
2 shallots, minced
1 bay leaf
1/4 cup flour
1/8 tsp cayenne pepper
3 cups milk
10 oz grated sharp white cheddar cheese
10 oz grated Gruyere cheese
6 oz velveeta, cut into 1/2" cubes
1 oz blue cheese, cumbled
freshly ground black pepper, to taste

Directions:
1. Heat oven to 375 degrees. Bring a 4-qt saucepan of lightly salted water to a boil. Add pasta and cook, stirring occasionally, until cooked halfway through. Drain pasta; set pasta aside. Tear bread into small pieces and transfer to the bowl of a food processor. Process until finely ground, set aside. Return pan to medium heat and melt 3 Tbsp butter. Add bread crumbs and stir to combine. Transfer bread crumb mixture to a plate and set aside.
2. Wipe out pan and set over medium heat. Melt the remaining butter and add the paprika, thyme, shallots, and bay leaf; cook, stirring often, until shallots are soft, about 5 minutes. Add flour and cayenne and stir until mixture thickens, 1 minute. Whisk in milk and cook, continuing to whisk often, until sauce has thickened and coats the back of a spoon, about 10 minutes. Discard thyme and bay leaf and remove pan from heat. Stir in cheddar, half the Gruyere, velveeta, and blue cheese; cintinue stirring until smooth. Stir in pasta and season sauce with salt and pepper. Transfer mixture to an 8x8 baking dish. Sprinkle with remaining Gruyere over the top of pasta and then top with bread crumbs. Transfer baking dish to an aluminum foil-lined baking sheet and bake until macaroli and cheese is golden brown and bubbly, 30 minutes. Let cool 10 minutes before serving.