Get 2 mixing bowls: 1 large bowl for mixing all the ingredients and 1 medium bowl for mixing the flour and starch. Do not add the Xantham Gum.
Add rice flour, quinoa four, potato starch and cornstarch / tapioca starch into the medium bowl. Use a combination of Tapioca and Corn Starch. Mix with a fork.
Add the sugar, salt, eggs, vanilla and milk into large bowl. Mix or blend thoroughly until all ingredients are dissolved then add melted butter and mix again.
Slowly add the flour and starch from the medium bowl to the large bowl while constantly mixing or blending.
Finally add the Xantham gum. I find 1/2 teaspoon is perfect however some may prefer less or more. You can add it in smaller increments however keep in mind that I have found that Xantham gum does take a few minutes to activate. Therefore if you add it in smaller increments make sure you blend in between the increments for at least 2-3 minutes to see the full effect.
Let the mixture sit for at least 30 minutes to flatten out the batter or in the Fridge overnight.
Pre-heat a 12" pan to half the temperature of what you would cook regular pancakes (medium-low), this should take about 5 minutes. From my experience the rice flour and starches need a longer and slower cooking process otherwise the pancake will be crispy on the outside and mushy on the inside. To get a golden crispy look and texture, pre-grease the pan with butter before cooking each pancake.
Place no more then 1/2 cup of the pancake batter into the centre of the pan and rotate/tilt the batter to the edges of the pan. You want the pancakes to been slightly thicker then a crepe. Every pan is different so experiment to get the right dose per pancake.
Cook for at least 2 minutes on the first side and 1 minute on the second side.