Preheat oven to 375° F. Grease the inside of 4 (6 oz.) ramekins with butter.
Spoon 2 tbsp of salsa into each ramekin. Divide the chopped green onion evenly between the ramekins. Sprinkle 1 tbsp of cheese on top of the green onions. Crack 1 egg into each ramekin and season with a little sea salt and pepper to taste.
Place the ramekins on a small baking sheet or dish (to help transfer into and out of oven) and bake for 12-15 minutes for runny yolks, 15-18 minutes for soft-cooked yolks or 20 minutes for hard-cooked yolks. Sprinkle the cilantro on top of each one and serve.
Notes
Depending on your oven, you may want to rotate these about halfway through the cooking process. I know my oven doesn't cook evenly, so I rotated mine.