1 1/2 lbs. fillet steak
1 lg. onion
4 oz. mushrooms
1/2 pt. soured cream or 1/4 pt. stock
Salt & pepper
4 oz. butter
1/2 oz. flour
1 tbsp. tomato puree
1/2 tsp. made mustard

Cut fillet into neat, thin strips 1 inch long. Season well and set aside to allow meat to absorb the flavor. Slice onions thinly, mushrooms thickly and fry both in the butter until onion becomes transparent. Add meat and continue cooking for a few minutes. Add flour, puree, mustard and liquid. Heat gently and simmer for 15 minutes according to taste. Serve with rice and a green salad.