In a bowl, mix sour cream, condensed milk, lime juice, and lime zest. Slowly add in egg yolks and whisk together.
Pour the mixture into mini mason jars and cover each mason jar with tin foil.
In your pressure cooker, add 1 2/2 cups of water followed by the trivet that came with your pressure cooker.
Place the mason jars in the pressure cooker, and cook on high pressure for 12 minutes.
lace the mason jars in the fridge to cool for at least 4 hours before serving.