Preheat oven to 425 degrees. Break the woody stems from the asparagus spears.
Place the prepared asparagus on a baking sheet. Drizzle with the olive oil. Toss with your hands to coat the spears. Sprinkle with a little bit of black pepper and salt if desired.
Bake for 15 - 20 minutes, turning halfway during cooking.
While the asparagus is roasting, prepare the white cheddar sauce. Start by melting the butter in a medium sized sauce pan over low heat.
Whisk in the flour. Cook and stir until smooth and bubbly, about 2 minutes.
Gradually whisk in the milk. Stir in the salt, pepper, and nutmeg.
Increase the heat to medium high to bring the sauce to a low boil. When the mixture starts bubbling, remove from heat.
Stir in the cheddar cheese until melted.
Serve the roasted asparagus with a generous portion of the cheddar cheese sauce. Sprinkle with a small amount of nutmeg to finish if desired.
This recipe makes enough cheese sauce for serving on top of the asparagus plus more on the side. You could easily double the amount of asparagus and keep the cheese sauce portions the same to serve 8 people instead of 4.