Steps
1. Cook the elbow macaroni according to package instructions until al dente. Drain and set aside.
2. In a saucepan, melt the butter over medium heat. Whisk in the flour to create a roux and cook for 1-2 minutes until golden.
3. Gradually whisk in the milk, stirring constantly until the mixture thickens and is smooth.
4. Remove from heat and stir in the cheddar and Gruyère cheeses until melted and creamy.
5. Add the cooked macaroni to the cheese sauce, mixing well to combine.
6. Drizzle in the truffle oil, and season with salt and pepper to taste.
7. Serve hot, garnished with fresh parsley if desired.