Place the quinoa and chicken stock in a nonreactive rondeau. Bring to a boil. Simmer, covered, over low heat until all of the liquid has been absorbed. Stir frequently. Spread out in 2" (5 cm) stainless-steel hotel pans. Loosely cover with film wrap. Refrigerate. Allow to cool. Stir frequently. Break the eggs into a stainless-steel mixing bowl. Whisk until blended. Add the cooled quinoa to the bowl. Sprinkle the rice flour over the top of the quinoa. Mix together with a rubber spatula. Season to taste with salt and pepper. Spray a heated flat griddle or grill with pan spray. Place a 4" (10 cm) egg ring on the griddle. Place a scoop of the quinoa mixture in the centre of the ring. Use a small heat-resistant spatula to pack and smooth out the high edges of the quinoa so it is level in the ring. Lightly brown on both sides. Remove the ring. Grill until just cooked through.