*Use whichever gluten-free all-purpose flour mix you like best. Most of the time I use my own gluten-free flour mix, which is a very economical choice. It consists of three parts Asian white rice flour (much more finely ground that typical white rice flour) and two parts cornstarch. I typically make 5 lbs of this mix at a time. I use three 1-lb bags of Asian white rice flour and two 1-lb boxes of Argo cornstarch. Mix well, but gently in a very large bowl and then transfer to airtight storage containers (like Tupperware).
I’m sure you could make this in an 8-inch square casserole dish or something similar if you don’t have a deep-dish pie plate. I used 5½ peaches yesterday–that’s what was needed to fill my pie plate, yet leave enough room to pour over the crust. Also, for you folks who don’t use gums, as I've noted, this recipe can be made without xanthan gum successfully as well.
Readers have made my Crustless Apple Pie successfully using both commercial egg replacer and flax gel eggs, so either of those methods *should* work in this recipe as well.
if you want a true pie and not more of a fruit cobbler, you need to be sure to drain the juice from your sliced peaches and save it for another use (e.g., breakfast smoothie? ice cream topping?). If you don’t drain off the juiciness, again, you’ll have more of a cobbler than a pie. For the batter to seep down between the peach slices and form a bottom crust, you need “drier” peaches. Either version will be delicious, of course.
Placing the pie on a baking sheet will save you from any spillage due to overly juicy peaches, but if you do that, the pie will require a slightly longer baking time.