In a medium size pan, melt butter at low heat and pour flour while
mixing with a wooden spatula. Keep on mixing while cooking on
LOW heat for about 2 minutes, until butter and flour are completely
melted.
Let this cool down a little. Remove it from the stove and gradually
add the hot milk (take out the bay leaf) while constantly mixing
with a whisk in order to avoid lumps. This will create a perfectly
smooth sauce.
Cook for 10 more minutes on medium heat, mixing this preparation
often. We call this "bechamel" sauce. When the bechamel
is ready, reduce heat to low and add the cream. Add salt, pepper
and grated nutmeg and keep it on low heat for 5 more minutes.
This delicious sauce will accompany any vegetable or white meat.
At any time, you can add milk if you want to make this sauce thiner.
If you choose to add fish stock when you add the milk, it will
be perfect to accompany any fish.