Step 1

Boil pasta in salted water until al dente, drain, and return to the pot.

Step 2

As the pasta cooks, warm half-and-half in the microwave for 1-2 minutes. In a large saucepan, melt the butter over medium heat. Once melted, add flour and whisk for about a minute; the flour should start to take on some color.

Step 3

Gradually add the warm half-and-half to the flour mixture, whisking constantly until incorporated, then slowly add evaporated milk. Heat for about 5 minutes; it will be slightly thick.

Step 4

Remove the roux from the heat and add all but ½ cup of the cheddar cheese. Whisk until combined. Add thyme, mustard, salt, and pepper.

Step 5

Pour over cooked pasta, stirring to combine. Place in a baking dish and sprinkle with remaining cheese.

Step 6

Cover with aluminum foil and bake for 20-25 minutes until bubbly and the top layer of cheese has melted.