Grapefruit Avocado Salad

2 medium pink grapefruits
1 medium shallot, minced
2 tablespoons chives, chopped
1 teaspoon white wine vinegar
2 tablespoons olive oil
2 medium avocados, sliced 1/4 inch thick
kosher salt
freshly ground black pepper

With a sharp knife, cut the skin and all of the white pith off of the grapefruits.
Working over a bowl, cut between the membranes to release the sections; set them aside.
Squeeze the juice from the remaining membranes into the bowl. (You should have at least 2 tablespoons of juice.)
Add the shallot, chives, and vinegar to the juice.
Whisk in the olive oil.
Set aside and let stand for a few minutes to meld flavors.
Arrange the sliced avocado and grapefruit sections on plates.
Drizzle dressing over the salad.
Season with salt and pepper. (Serves 4)