2loavessourdough bread, round, or pumpernickel bread or 1 of each
Thaw the frozen spinach fully and drain well. Wring it out a bit with your hands to make sure it is well drained.
Chop the spinach. Mix it with the other ingredients, except the bread, and refrigerate it to let the flavors meld together.
Hollow out one of the loaves of bread with a knife, cutting the bread you remove into 2 inch chunks for dipping. I have specified 2 loaves of the bread because if you just get 1 there always seems to be dip left over and no bread to use it up. Cut the second loaf of bread into cubes for dipping.
Place the hollowed out loaf of bread on a serving plate and fill the hollow with the chilled dip. Arrange the cubes of bread around the loaf and use them to dip.