Saute the onion in half the butter. Turn on the oven at 200 degrees.
Add spinach, cook for a few minutes, until spinach is dry. If you bake not in a frying pan, but in a different form, then put the onion and spinach there.
Mix a small amount of milk with flour and salt so that there are no lumps. Add all the milk and processed cheese.
Drive eggs into spinach and onions. Add fill to the form.
Sprinkle with breadcrumbs, pour over with melted butter.
Place in the oven for 20 minutes.