Mushroom Stroganoff

Grocery List 2 tbsp vegetable oil , divided1 large onion, sliced2 1/2 cup mushrooms , sliced3 tbsp butter2 tbsp flour 2 cups / 500 ml beef broth or mushroom stock (or whatever stock you have on hand)1 tbsp Dijon mustard150 ml / 2/3 cup sour cream / yogurtSalt and pepper How to make it Turn heat to medium high. Add butter, melt. Then add onions, cook for 1 minute, [...]