Oil and Egg Tempera

My last work on last year's portrait painting course was a portrait of an actor. I wanted to learn how to use egg tempera, unfortunately I did not documented the sequence, but it was as follows:
1. Portrait drawing with charcoal.
2. Fix the charcoal with air spray.
3. Prepare the egg tempera. There are different methods, I use the easy one: mixing pigments (Sonnelier; burnt sienna and white) with the egg yolk (I used five eggs), I did not use any water on the mix (some recipes use distilled water, lineseed oil, etc.)
4. I applied the egg tempera to the background, then shadows and after lights. I had to work rapidly since the egg tempera dries very fast
5. The rest was oil painting, several sessions.
And the result is this: