This lighter mac 'n cheese is as deliciously creamy as a traditional version; the perfect texture comes from the evaporated milk, reduced-fat cheddar and Neufchatel cheese. The secret ingredient -- which makes these creamy ingredients go a long way -- is cooked cauliflower blended into the sauce. You don't know it's there, but it adds value to your meal by stretching the sauce while sneaking in a serving of vegetables.
Whisk the egg, evaporated milk, mustard powder, cayenne, nutmeg, garlic, and salt and pepper to taste in a bowl; set aside.
Bring a large pot of salted water to a boil. Cook the cauliflower until tender and almost falling apart, 8 to 10 minutes. Remove with a slotted spoon or sieve. Add the pasta to the same water and cook until al dente, about 10 minutes. Drain, reserving about 1/4 cup pasta water. Save the pot.
Put the egg mixture and cheeses in the empty pot and cook over medium-low heat, whisking constantly, until the cheese melts and the sauce begins to thicken, about 6 minutes. Remove from the heat. Add the cauliflower and puree with an immersion blender until smooth and light. Stir in some of the reserved pasta water to adjust the creaminess of the sauce as needed. Add the pasta to the sauce and toss, season with salt and pepper. Serve, sprinkled with breadcrumbs if desired.
This creamy cheese sauce is the perfect lighter stand-in for the traditional in multiple uses, such as a topping for steamed broccoli, baked potato or asparagus.