Beef Stroganoff

1-1/2 - 2 lbs. petite sirloin--thinly sliced while partially frozen

thinly sliced onion (optional)

2 stalks celery, diced (optional)

2 Tbl. vegetable oil, or as needed

Fresh sliced mushrooms OR 1 can mushrooms, drained

1/3 cup flour

1 cup milk, in 1/3-cup increments as needed

1/2 cup sour cream (or more, as desired)

1/2 tsp. salt, or as desired

pepper as desired

1/2 tsp. paprika

In skillet (NOT non-stick) brown sirloin, onion, and celery in oil 'til browned and little bits of frying are on bottom of pan.  Stir in flour until there is no white showing.  GRADUALLY add milk, stirring until thickened...don't add too much to make it too runny.  Stir in sour cream and seasonings as desired.  Serve over rice or egg noodles.