Mac n cheese

So my sister just sent me a facebook message, she wants to make Mac n cheese, but doesn't know how. Here's my recipe, sorry no picture.

1 16oz package elbow macaroni
4 cups milk
1 cup gruyere cheese, grated
2 cup cheddar cheese, grated (sharp or mild, I prefer sharp)
2 tablespoons butter
2 tablespoons flour
1/8 teaspoon nutmeg
salt & pepper to taste
nonstick cooking spray

Cook macaroni as you would normally cook pasta. Heat a large saucepan to medium heat, add the butter and as soon as it starts melting add the flour.  With a wooden spoon scrape the bottom of the pan mixing the flour and butter together, add the nutmeg. Start adding the milk half a cup at a time, mixing and scraping the bottom of the pan - you don't want any lumps. As soon as it starts to thicken add more milk until all of the milk has been added. Let simmer until it thickens, you will know that it's ready when the milk stays on the back of the spoon. Add the cheeses and stir. Taste and add salt and pepper as needed. (the cheeses are a bit salty) Add the macaroni and stir.

Take a baking dish and spray with the nonstick cooking spray. Pour the macaroni in the baking dish and bake at 350 degrees until it browns on top. Enjoy!