By popular demand, here is the recipe.
2 packets of hollandaise sauce mix (dry). Typically you will also need 2 cups (one pint) of whole milk*, and 1/2 cup (a whole stick) of butter to prepare it.
1 cup shredded parmesan or parmigiano reggiano
2 10oz packs of frozen chopped spinach, thawed and pressed as dry as you can (use paper towels, or squeeze through a colander).
Prepare the hollandaise sauce mix per its instructions.
When then sauce is ready, remove from heat; add the shredded parmesan and mix until combined and melted.
Add the chopped spinach, mix until combined, and return to low heat just until it is warmed through; overcooking will ruin the consistency.
Makes about 3 cups, enough for 12 quarter-cup servings (or 12 four-ounce servings).
Excellent as a side dish for a good steak.
* Whole milk, people, whole milk. None of this 2% or lowfat junk. It's decadent; deal with it.
UPDATE (2014-02-19): Use 3 packs of spinach if you want it a little less creamy. Lately I've preferred it that way.