Modifications: the creamed spinach portion of this recipe is gluten-free. To make the entire dish gluten-free, just use your favorite gluten-free bread for the toast portion.
Regarding draining/wringing frozen spinach: If you've got one, I've found the simplest way to remove a majority of the liquid from thawed frozen spinach is with a potato ricer (I have
this one). It takes about three presses (and maybe 2 mins?) to wring the liquid from one thawed 16 oz bag -- easy!