Finely chop the onion. Heat a frying pan with vegetable oil, fry the onion.
Finely chop the mushrooms and pork. Add them to the onion in the pan, fry for 10-15 minutes. Add salt and pepper to taste.
To prepare the sauce, pour flour into a heated frying pan and bring it to a golden color. Add butter. Then pour in milk and simmer for a few minutes. Finally, pour in sour cream. Simmer until the sauce thickens.
Grate the cheese. Put the mushrooms and meat in the cocotte dishes, add the sauce and sprinkle with cheese. Bake in the oven for 15 minutes. As you can see, julienne with pork is very easy to prepare.