Start by peeling the skin of the onion and garlic and dice them up finely.
Also, dice the chicken breast up into very small pieces - I chose to dice up the chicken into smaller than bite-sized pieces.
If you are using olives, chop them up as well so all the ingredients are prepped and ready.
Bring the water to a boil in a large pan.
Add the pasta to the water along with a couple of pinches of salt. Let pasta boil until it is barely al-dente (about 2 minutes less than package specifies to boil it for), stirring often so the pasta does not stick.
When done, drain the pasta water into a container and set pasta and pasta cooking water aside.
Add oil or butter to the large pan.
Add in the za’atar and pepper and stir so the spices toast - about a minute or so.
Add in the chopped onion and garlic and stir well for about 5 minutes.
Then add in the finely diced chicken and stir well until the chicken is cooked. As the chicken is diced so finely, it should cook in about 10 minutes.
Add in the cooked pasta and pasta water and toss well, using some kitchen tongs for about a minute.
Stir in the Pecorino Romano and toss.
Add in the olives if you are using them and toss well.
After this Za’atar Cacio e Pepe has rested for a few minutes, dig in and enjoy!