1 tbsp butter/olive oil
1 small onion finely chopped
3 garlic cloves crushed
25- g (1lb) mushrooms sliced
1/2 tbsp flour
3/4 cups stock/broth
1/2 cup sour cream
1/2 tsp Dijon mustard
Salt and pepper to taste
Set a large sauté pan or large skillet over medium-high heat then add the butter/olive oil.
Add the chopped onions and sliced mushrooms and cook for 10 minutes, then add the garlic and continue cooking until the mushrooms are golden brown and the onions are soft. Season with salt and pepper.
Stir in the flour and cook for a minute then pour in the stock and whisk until the flour has been mixed into the liquid.
Reduce the heat then gently simmer for a few minutes until the sauce has thickened slightly then stir in the sour cream and mustard.
