Mushrooms again, this time in stroganoff

This is another mushroom recipe in my evergrowing mushroom repertoire. It is a lovely quick dish to serve during the week or whenever I am peckish for mushrooms (this happens surprisingly often), but not in the mood of making mushroom quiches, salads, soups or roasting mushrooms with carrots. I found the recipe on the reverse of a paper bag provided by Tesco for packing their mushrooms in - it must have been when I first arrived in Edinburgh back in October 1998, and I've been making this dish regularly since then.

Mushroom stroganoff
(Seenestrooganov)
Serves 4, adapted from Tesco



~ 500 grams (chestnut) mushrooms
1 medium sized onion, finely chopped
1-2 Tbsp butter
15o ml vegetable stock
1 tsp strong & sharp mustard
1 tsp concentrated tomato puré
150 ml sour cream or crème fraîche
half a lemon
chopped fresh flatleaf parsley

Heat the butter in a large frying pan, add chopped mushrooms and finely chopped onions. Sauté on medium heat for about 10-15 minutes, until the onions have began to soften.
Add tomato puré, mustard and the stock. Bring to the boil and simmer for 5 minutes.
Remove the pan from the heat, season with salt and pepper, and gently stir in sour cream. Heat through, but don't let it boil again (this is more important with sour cream than crème fraîche, because the first can curdle easily).
Season with lemon juice, sprinkle with chopped parsley and serve with boiled (new) potatoes and some salad greens.