First, fill a large stockpot halfway up with water. You'll want to be able to submerge all of your mason jars with water, so keep that in mind.
Next, screw your sous vide to the side of your pot and turn to 172ºF. While your water bath is heating up, prepare egg bites.
Thoroughly spray 9 4-oz. mason jars with nonstick cooking spray. Then, spoon about a tablespoon of shredded cheese onto the bottom of each mason jar.
Crack 10 eggs inside a medium bowl or Pyrex. Add the milk and whisk until scrambled.
Fill each mason jar up about 3/4 of the way full with the egg mixture. You should get about 9 egg cups. Give each egg cup a little stir and then season the tops with salt and pepper, to taste.
Now it's time to screw on the lids of your mason jars. You want to make sure that you don't fully tighten your mason jars so that they do not explode in the water bath. Screw on tops and then unscrew one turn.
Submerge mason jars inside of the water bath. You should see lots of bubbles come to the top. This is good!
Set the timer for 1 hour and let cook.
Once the timer goes off, use tongs to remove the mason jars (they will be hot) and then unscrew them. Your egg cups should feel like a souffle. If they're still runny, you need to cook them longer. If you're ready to eat, grab a fork!