In a large bowl, combine mayonnaise, sour cream, chopped water chestnuts, minced onion, drained spinach, and vegetable soup mix.

Mix well until all ingredients are thoroughly combined.

Cut a circle in the top of one loaf of round crusty bread, creating an opening.

Hollow out the inside of the bread loaf to create a bowl.

Pour the spinach mixture into the hollowed-out bread bowl.

Cut the remaining loaf of bread into cubes.

Serve the spinach dip in the bread bowl with the bread cubes for dipping.