In a large cast-iron or non-stick skillet, melt ½ tablespoon butter over medium-low heat until the butter starts to foam. (Tip: If using a stainless steel or cast iron skillet, heat it for several minutes on medium-high heat (until a drop of water dances on the pan), then reduce the heat and add butter. This will make the skillet act non-stick.)
Add the eggs and sprinkle with a pinch of kosher salt and a few grinds of black pepper.
Sunny side up: Cook for 2-3 minutes, until the whites are firm but the yolks are still runny. Don’t flip! Remove the eggs to a plate and serve.
Over easy: Cook for 2 to 3 minutes, until the white is firm but the yolk is still runny. Flip and cook 20 to 30 more seconds, keeping the yolk still liquid.
Over medium: Cook for 2 to 3 minutes, until the white is firm but the yolk is still runny. Flip and cook 1 more minute until the yolk is jammy and just barely runny. (Press the yolk gently with your finger to assess doneness.)
Over hard: Cook for 2 to 3 minutes, until the white is firm but the yolk is still runny. Flip and cook 2 more minutes until the yolk is fully cooked through. About 1 minute in, gently press the yolk with a spatula to make sure it’s broken.