Mix together 1/2 c. chopped onion 1/4 cup celery,1/2 c. sour cream 1/4 c. mayo 2 Tab lemon juice,1 Tab fresh choped parsley harseradish to taste 1 tea prepared mustard salt pepper 1 tea marjoram 1 pound of thin sliced mushrooms Toss 1 pound of cooked roast beef cut into thin strips or chopped in f/p and mix them together saute a few minutes in butter mix with rest of ingredients and some shredded lettuce put into a half pita bread and enjoy makes at least10 pita sammies or 4-6 salad servings