04Beat the eggs in a large bowl and add 1/2 teaspoon salt. Stir in the quinoa, the onion and spinach mixture, the Gruyère, and the sage. Add freshly ground pepper and stir the mixture together. Scrape into the gratin dish. Sprinkle the Parmesan over the top and drizzle on the remaining tablespoon of olive oil. Place in the oven and bake until nicely browned on top, about 25 minutes. Remove from the heat, allow to sit for about 5 minutes, and serve.