Quick Beef Stroganoff - with Rice

A busy life with a family means hearty, nutritious meals that can be made in minutes. ( or half and hour: tops)  This is a variation of a Veal Goulash recipe I had that takes much longer to cook and uses stewing veal or beef as opposed to leaner, finer cuts.
Just why is something that I ponder about, but I do notice many young people are lacking this instinctive knack of creating a meal with whatever is in the fridge, so I have posted this recipe or "throw – together," as I prefer to think of it, for their benefit. Established cooks most likely will have this or a variation of this in their repertoire.

INGREDIENTS:
1 onion, 2 stalks celery, a quantity of beef /bbq beef/ beef schnitzel or similar cut, enough to feed the required amount of people, sour cream, tomato paste, handful- 1 cup of chopped mushrooms, 1 cup chicken or beef stock ( or 1 cup water and 1 chicken/beef stock cube)

Method:
1. Cut beef along the grain and cook on moderate to high heat, quickly, almost till done. Remove and keep warm.

2.  Saute some finely chopped onion and celery in a dash of olive oil till onion is transparent.
3. Add mushrooms,  and cook briefly, for several minutes.
4.  Add 3 tbspns of tomato paste ( or whatever quantity the sachet comes in) and 1 cup Chicken or beef stock and cook for about 5 minutes or till sauce has thickened.
5.  Return cooked beef to pan and stir through 1/2 cup sour cream. ( Substitutes for sour cream could be whipping/pouring cream, evaporated milk, full cream milk ( sauce may be more runny)
6. Serve with nutty /white rice ( see recipe on next post)
Recipes for preparing Brown and White rice: Just what is the difference?

This dish is also nice with crusty baguettes/ breads.

Enjoy!