Step 1

Preheat oven to 325°F. Grease a 9 x 13-inch baking dish and set aside.

Step 2

In a large pot of salted boiling water, cook pasta for 1 minute less than the package suggestion for al dente (about 8 minutes). Drain and toss with a drizzle of olive oil to prevent sticking.

Step 3

While the pasta boils, melt butter in a large Dutch oven (about 6-7 quarts) over medium heat. Add flour; cook, whisking constantly, for 1 minute. Very gradually, whisk in the milk and half-and-half. Bring to a boil over medium heat, whisking constantly. Remove from the heat.

Step 4

Whisk in the Worcestershire sauce. Gradually add all of the Velveeta cheese and half of the cheddar cheese (1 ½ cups). Stir until the cheese is completely melted and smooth. Stir in the salt, dry mustard, pepper and nutmeg. Add cooked, drained pasta and stir to coat.

Step 5

Transfer to the prepared baking dish. Sprinkle remaining 1 ½ cups of grated cheddar on top. Bake for 15 minutes, or until cheese is melted on top and the sauce is bubbly.

Step 6

For a crispier, browner top, pop the dish under the broiler for 2-5 minutes.