Mushroom stroganoff

1) Heat a the oil in a deep frying pan over a medium heat
2) Add the onion with a pinch of salt and cook gently for 5-7 minutes or until soft.
3) Add the garlic to the pan and continue to cook for two minutes then add the sliced mushrooms.
4) Continue to cook gently for a 5-6 minutes, or until the mushrooms are tender and golden-brown.
5) Add the mustard and paprika and mix well so that everything is coated.
6) Add the stock, stirring as you pour it. Simmer gently for five minutes. 
7) Remove the mushrooms from the heat, stir in the soured cream along with the juice of two lemon wedges and mix together.
8) Season to taste.
9) Serve with pasta, green beans and wedges of lemon.