1. Without putting oil in the pot, add flour and fry until slightly yellowed.
2. Push the flour aside, pour a little oil into the pan, and fry the sliced mushrooms until soft.
3. Pour the fried flour and mushrooms into a mixer, add a bowl of water to make a slurry.
4. Pour the beaten mushroom paste back into the pot, add 50ml of milk, a spoonful of salt, and an appropriate amount of pepper to a boil. Stir while boiling until it is thick.
5. Cut bacon into small pieces and sauté until fragrant.
6. Put the soup in a bowl and sprinkle with pepper and bacon.
