Step 1

Preheat oven to 325° and lightly spray a medium casserole dish.

Step 2

Bring a 10 or 12-inch skillet of water to a boil, add florets and cook 3 mintues. Use a slotted spoon to transfer the broccoli to an ice bath and set a timer for 3 minutes. Then transfer to paper towel (or clean kitchen towel) lined pan. Set aside.

Step 3

Bring a pot of salted water to boil. Once boiling, add pasta and cook according to package directions.

Step 4

In a 10-inch skillet, arrange bacon and cook until crispy. Transfer bacon to a cutting board to cool, then finely chop.

Step 5

To the bacon fat (see notes) add butter. Once melted, stir in flour and cook 1 to 2 minutes. Whisk while pouring in milk. Simmer until slightly thick and creamy. About 6 minutes.

Step 6

Reduce heat to low and season the cream sauce with ground mustard, white pepper, nutmeg and freshly ground black pepper. Whisk to incorporate.

Step 7

Add half of the grated cheddar and fontina to the cheese sauce. Continue to whisk until smooth. Taste and season with kosher salt, more or less to taste.

Step 8

To the cheese sauce, add the blanched broccoli and 3/4 of the chopped bacon. Stir to combine and transfer to prepared pan. Sprinkle with the last of the cheeses and bake for 10 to 12 minutes.

Step 9

Use oven mitts to carefully remove. Move the oven rack to the highest position and turn on the broiler. Slide the mac and cheee under the broiler for 2 minutes or until the top is golden.

Step 10

Sprinkle with remaining bacon and serve immediately.