Thaw puff pastry at room temperature 30 minutes.
Drain spinach well, pressing between layers of paper towels, or cheesecloth.
Stir together spinach, artichoke hearts, and next 5 ingredients.
Unfold pastry, and place on a lightly floured surface or heavy-duty plastic wrap.
Spread half of the spinach mixture evenly over pastry sheet, leaving a ½-inch border.
Roll up pastry, jellyroll fashion, pressing to seal seam; wrap in heavy-duty plastic wrap.
Repeat procedure with remaining pastry and spinach mixture.
Freeze 30 minutes; cut into ½-inch-thick slices.
Mix 1 egg and 1 tablespoon water in a small dish. Brush egg mixture on each piece before baking.
Bake at 400° for 20 minutes or until golden brown.
