Cut the avocados in half and discard the pit. Using a spoon carefully scoop out the flesh from the shells. Add it to a large bowl with the chopped scallions and serrano peppers. Immediately squeeze some lime juice over the top and hit it with a good sprinkling of sea salt.
Use a spatula to fold everything together then taste. Add more of both salt and lime until your taste buds are happy. Fold in the cilantro and red onion and serve sprinkled with the chives and extra lime wedges.
To keep the guacamole from turning brown serve fresh as soon as you mix it. If made in advance remember to store in a glass container with a layer if thinly sliced lime or lemons on top. Cover with a tight lid and keep chilled for up to 3 days.