Combine the chicken, onions, 2 cups feta cheese, cream and cumin. Season with salt and pepper. Put some of the mixture onto each of the 8 tortillas. Roll them up and put them in a large oven dish.
Mix the salsa, yoghurt, a little cream cream and the green onions in a different bowl. Season. Pour this sauce over the tortillas and sprinkle with the remaining feta cheese. Bake for 30 min.