Preheat the oven to 450 degrees and line the cookie sheet with parchment paper.
Separate the egg whites from the egg yolks, putting the whites in a standing mixer and each yolk into 6 individual red solo cups.
Add 1/4 teaspoon cream of tartar to the egg whites.
Turn on the mixer to medium to high speed and mix until stiff peaks form.
Add in the black pepper.
Once mixed, add in the chopped ham, mozzarella, and chives.
Lightly fold the mixture until combined.
Using an ice cream scoop, make 6 "clouds" of the egg white mixture on the parchment-lined cookie sheet.
Using the back of a spoon, make a small cavity in the middle of each cloud for the yolk.
Place egg white mixture into the oven for 3 minutes.
Pull out and lightly place a yolk into each of the egg clouds.
Place back into the oven for 2 minutes. Once done, pull out and serve immediately.