Step 1

Make the pasta according to package instructions.

Step 2

Preheat the oven to 400ºF (205°C).

Step 3

Separate 2 tbsp. of milk from the cup and combine with the cornstarch in a small bowl until dissolved.

Step 4

Heat the butter in a non-stick pan. Add the milk and cornstarch mixture, and stir until it starts to get thick.

Step 5

Add the cheeses, mustard, salt, and pepper. Cook for 5 more minutes - stirring occasionally -or until the cheese has melted.

Step 6

Add the cooked pasta and combine it with the cheese sauce.

Step 7

Transfer to a baking dish, top with cheddar cheese, and bake for 10-15 minutes, or until golden brown on top.