white mushroom with gratin sauce

I ate this at Miam Miam and I loved it. It was selling at $8.90++. It is too exp to eat there often, so I have to think of how to make it at home. It is my first attempt to make something with white sauce. I searched for recipes online, and finally I came up with this combination. It works pretty well, tasty and easy.


ingredients
one pack of white button mushrooms (about 8 pieces)
220 ml fresh milk
20g salted butter
4 tsp plain flour
a pinch of salt
some pepper
shredded mozzarella cheese


Steps:
1. melt the butter in a small pot. Low heat. Do not burn the butter.
2. add the milk and flour. stir and mix well.
3. add in the seasonings: salt and pepper. (according to your own preference)
4. add in the mushrooms. Mix well and you can transfer to a baking tray or ramekin.
5. Preheat the oven at 170 degree.
6. Put cheese on the top of each mushroom.(more cheese tastes better)
7. Bake the mushrooms for about 18 min at 170 degree. You will see the cheese become brown. It is ready. Serve hot.