Ingredients

• Sea salt to cook macaroni
• 1 (16 ounce) pkg macaroni
• 1/4lb bacon, diced
• 1 medium onion, diced
• 5 Tbsp unsalted butter
• 6 Tbsp all-purpose flour
• 1 Tbsp Dijon mustard
• 2 1/2 cups whole milk
• 2 cups heavy cream
• 1 sprig fresh thyme
• 1 bay leaf
• 1/2 tsp salt
• 125g grated fontina (1 1/2 c)
• 30g mild blue cheese such as Trader Joe's Cow/Goat (1/2 c crumbled)
• 70g grated Gruyere (3/4 c)
• 70g grated white Cheddar (Australian) (3/4 c)
• 70g grated Parmesan (3/4 c)
• 3 Tbsp chopped Italian parsley
• 1/4 cup bread crumbs

Directions

1. Preheat the oven to 450 degrees and butter a 13x9 baking dish.
2. In a large pot of boiling water add salt and macaroni.
3. Cook according to packaged directions.  Before draining, keep at least 1 cup of water.
4. In a large frying pan, saute the bacon.
5. Remove bacon when crispy and set aside.
6. Create a cheese mixture of fontina,  Gruyere, white Cheddar, and Parmesan. (Note, do not use blue cheese)
7. Mix together bread crumbs, blue cheese, and 30g of cheese mixture
8. Without draining the grease, add the onions to the pan.
9. Cook until tender. Add the butter.
10. When the butter is melted, mix in flour with whisk until smooth.
11. Whisk in the mustard.
12. Slowly add milk and cream while continuing to stir.
13. Add the thyme, bay leaf, and salt. Let come to a simmer and stir frequently for 15 minutes.
14. Strain the hot milk mixture into a bowl and discard the solids.
15. Continually stir the mixture while slowly adding in the cheese mixture.   You want to keep the mixture hot enough to quickly melt the added cheese.   Add reserved pasta water as needed to keep sauce stirrable.
16. Add the macaroni to the cheese mixture to coat.  
17. Add reserved pasta water until the mixture is nice and stirrable like a good quality thin cheese whiz.
18. Add the noodle mixture to a 13x9 baking dish.
19. Sprinkle bacon on top.
20. Sprinkle bread crumb mixture on top.
21. Back for about 20 minutes