Bring the broth to a boil in a saucepan. Rinse the quinoa in cold water, drain and simmer in the broth over a mild heat for about 15 minutes.
Roast the sunflower seeds (without fat) in a pan. Clean and wash the leek and cut into rings.
Mix the quinoa, leek and sunflower seeds and place in a greased baking dish. Whisk the eggs with the crème fraîche, season with the yeast spice, paprika, nutmeg, salt and pepper. Spread the egg mixture evenly over the casserole and sprinkle the cheese over it. Bake in a preheated oven at 200 ° C for 30 minutes.
You can get yeast wort in health food stores or in the well-stocked organic department in the supermarket.