Crock Pot Beef Tips

2 pounds stew beef or very lean roast cut up into big bite size pieces
1 can cream of celery soup (or mushroom if you like)
1 envelope onion soup mix
1 envelope brown gravy mix
1½ cup 7-UP (or Ginger Ale)
1 large onion cut into fourths
8 ounces of fresh mushrooms sliced (may use canned mushrooms too OR leave them out if you like)

Place beef, onions, and mushrooms (opt) in crock pot. 
Combine celery soup, onion soup mix, gravy mix in a bowl and stir well.  Add 7-UP to the bowl. Stir well.
Pour over the ingredients already in the crock pot. 
Cover and cook on low for 5-6 hours.
Serve over hot cooked egg noodles, rice or mashed potatoes.