Set pot of water to boil for the pasta & add pasta when water is at a rolling boil.
In a large pan over medium heat, heat onion and butter until onions are soft, sweet and lightly brown - add garlic at the end as it cooks much faster than onion.
Sprinkle the flour over the top of them and stir to make a roux. Add the milk a little at a time while stirring constantly. Don't panic if it's a little lumpy because you are making a cheese sauce anyway.
After thoroughly rinsing the bay scallops (they tend to be sandy) add them to the sauce in the pan and cook until the scallops are opaque. Add salt and pepper to taste.
Once the scallops are done, add the cheese and stir it up.
To plate, I garnished with goat cheese and fresh cracked pepper - very tasty addition.