Cook the macaroni in a pot of salted water to al dente according to package instructions. Once cooked, drain and run under cold water.
In a large saucepan, melt butter over medium heat. Whisk in flour and cook until the flour is incorporated. Cook for 1-2 minutes to cook off the flour flavor.
Turn the heat to low and add the milk, cream, mustard, and seasoning. Cook while stirring until the mixture thickens and there are no remaining flour clumps.
Remove from heat and stir in the shredded cheese.
Add macaroni to a 9x13-inch baking dish. Add the cheese sauce and stir to combine.
Top with crushed crackers.
Bake for 18 to 20 minutes or until bubbly. Do not overcook. You can broil for the last two minutes for the crackers to be extra crunchy.
Notes
Cheese: You can use your favorite cheese or a combination of cheeses. We recommend mild or sharp cheddar, havarti, gouda or gruyere.
Shred the cheese: I can’t stress the importance of not using pre-shredded cheese. Pre-shredded cheese is coated in a starchy film that prevents the cheese sauce from being creamy and silky.
Don’t burn your roux: When cooking down your roux, use a very low heat and stirring constantly.
Add the cheese correctly: It is really important to take the pot off of the heat. Add the cheese one handful at a time and stir until there are no lumps.
Storage. Store leftovers in an airtight container in the fridge for up to 3 days.
Reheat. To warm up the casserole, simply warm up the mac and cheese in a pan. Add a little water and cover with a lid; the steam will help melt the cheese and make creamy pasta.
Freeze. We don’t recommend freezing this mac and cheese as the cheese sauce can separate.