Spinach Dip

1 can (13.5 oz) spinach, drained
16 oz sour cream
3/4 cup mayo
1 pkg (1.4oz) Knorr vegetable soup mix
2 cans (8oz) water chestnuts, drained and chopped
3 green onions or 1 small onion, chopped

Mix until well blended. Cover and chill.