Fill a large straight-sided skillet with 2 inches of water and bring to a boil. Add vinegar and return to a boil. Break one egg into a small heatproof bowl. Placing lip of bowl in the water, gently tip the bowl to slide egg carefully into pan. Use a large slotted spoon to fold the edges of the white over the egg, for a neater edge. Repeat with remaining eggs.

Cook until whites are just set but the yolks are still soft, they should still move around inside, 1 1/2 to 2 minutes. Lift out eggs with a slotted spoon or small mesh sieve and briefly rest on bread to allow eggs to drain. Trim edges with a knife for a prettier presentation before serving on toast, if desired, and seasoned with salt and pepper.