You should be able to carefully turn the bowl upside down without it falling out.

3)In another bowl, put the egg yolks, cream cheese and cream of tartar then whisk together (no need to wash the beaters first) until smooth, pale and frothy.

Next, fold the egg whites, a spoonful at a time into the yolk mixture, be as gentle as you can with this so you don’t knock out too much of the air and finally fold in the nigella seeds and season with salt and pepper.