Heat butter in heavy skillet.
Saute onions gently until just limp.
Dredge veal, cut in 1-inchstrips, lightly in flour; brown evenly.
Season with salt and pepper.
Add parsley, tarragon and wine, cover and cook gently 4 minutes.
Add lemon juice; mix well.
Test for tenderness.
Slowly stir in sour cream.
Heat through, but do not boil.
Serve with noodles, dressed with butter and parsley.