In a large bowl, combine sour cream, mayonnaise, water chestnuts, scallions, and Knorr mix. Stir to combine.
Stir in spinach, using a spoon or spatula to break up and distribute any clumps of spinach. Cover and chill at least 2 hours or overnight. Serve with bread and fresh vegetables.
Water chestnuts: These are a crunchy, aquatic vegetable that grows under water. You can find them in almost any well-stocked grocery store. Look in the international aisle or the Asian foods section, as they’re often added to stir-frys.
Knorr vegetable mix: This used to be labeled “soup mix” but Knorr changes their packaging every once in awhile. By the way, the Leek Soup mix can also be used for this dip. (I love Knorr much more than Lipton brand, by the way.)
Frozen spinach: To substitute fresh spinach, use 1 pound fresh spinach leaves instead of the 10 ounces of frozen spinach. Cook according to the package directions and squeeze dry in a clean kitchen towel.
Yield: This recipe makes about 4 cups dip, enough for 16 servings, 1/4 cup each.
Storage: Store leftovers covered in the refrigerator for up to 4 days.
Make ahead: For the best flavors, let the dip chill at least 2 hours. Or, make it a day ahead and keep it in the refrigerator overnight.