Very lightly adapted from Simple Fare by Karen Mordechai. Karen notes that you should “[l]ook to make your eggs soft and a tad runny–soft enough to mash perfectly. You can also add the same amount of olive oil in place of the butter, if preferred.”
One of the many wonderful things about Simple Fare is the flexibility and encouragement to experiment that Karen brings to every recipe. Instead of rye and Pecorino, use sourdough and Manchego if you like, or buckwheat and Parmesan.
Find it online: https://tworedbowls.com/2017/04/26/buttered-eggs/