Rinse the oranges and avocados well. Using a sharp knife peel the oranges and slice them into thin slices. Arrange them on a platter.
Cut the avocado crosswise and remove the pit. Cut a thin slice off of the bottom of each half. Make a slit into the side of each avocado half and gently peel off the skin. Slice the avocado crosswise into thin slices.
Arrange the avocado slices between the orange slices and set aside.
Transfer the cilantro leafy tops to the bowl of a food processor. Add the lime juice, olive oil ad scallions and process until smooth. Season to taste with the sea salt.
Pour the scallion cilantro dressing over the oranges and avocado slices and serve with a sprinkling of the sliced scallion, freshly cracked black pepper on top and more dressing on the side. Garnish with extra cilantro leaves and enjoy !