Making a huge feast for NYE, thinking of including this as a side. Flour substitute? Gluty-free flour or another thickener?

Emily Gould, who recommended this recipe to me, makes it gluten-free using potato starch, though a much smaller amount than the flour called for. She said for this recipe just a couple tablespoons of potato starch would be good, and you can always add a little more liquid if it gets too thick.

jm, i looked at that recipe. another option would be to keep aside some of the spinach,onion and cheeses, and keep that dish separate for GF. That way, the others can have it as it was designed,plus the bread crumb topping.

But if you decide to go GF for the whole shebang, you might want to top the dish with pan- toasted quinoa, which is deliciously crunchy.

If you use a potato flour (Bob's Red Mill; they also do a potato starch) you can also use the potato flour as a small but essential component in biscuits that are particularly flaky and tender because off it. (If you need a recipe, let me know.) That way, it's not taking up room in your frig/freezer for one small use.

A starch thickener should work -- I'd probably go with potato.