Beef Stroganoff (Russian)

Description:
Another Russian dish, beef strips in a sour cream sauce, served with rice, bread, potatoes or pasta (it really goes well with any type of carbs!).

I served it with rice and French long green beans. I read a few different recipes online and made my best of and did my own version as recorded here.
It's a very quick, easy recipe, takes about 10 mins to prepare once you have the ingredients ready.

Ingredients:
300 gr beef (sirloin or tenderloin) cut in thin slices
2 onions
mushrooms
1 cup of sour cream
flour
salt
pepper
butter

Directions:
I got the butcher to slice the beef for me in thin slices, but if you get a chunk you'll have to do your own slicing, as thin as possible.

Peel, clean and cut the onions, and I cut two cloves of garlic as well (optional).
Clean and cut up the mushrooms.
Mix some flour (about 2 tablespoons) with salt and freshly ground black pepper. Spread the flour mix on a plate and coat each beef slice on both sides with the mixture.

Heat some butter (should be enough to cover the bottom of your frying pan) till it gets bubbly. Quickly fry the first batch of beef slices on both sides on high/medium heat. Make sure the butter and beef don't get burnt.
Take out the fried slices of beef and keep them aside on a plate.
Add a bit more butter and do the next batch till all beef slices have been nicely fried with brown colour.

Now keep the butter in the frying pan that you used to fry the beef and add the onions (and garlic). Add some more butter if necessary, make sure it won't stick to the pan and won't burn.
Take out the onions when nicely fried and keep aside with the beef. Add a bit more butter and fry the mushrooms till brown and soft.
Lower the fire, slowly spoon in the sour cream, make sure it won't get to a boil keep stirring. Add a bit of water as well (about half cup).
Add the onions and beef back into the mixture. Stir all through.

Serve hot with rice (or potatoes, bread, pasta).