6 small heads curly endive
1 large shallot
2 tablespoons white wine or Champagne vinegar
Pinch of salt
3/4 cup extra-virgin olive oil
Wash and spin dry the curly endive. For this salad, use only the blanched hearts and save the green leaves for cooking greens.
Peel the shallot and dice it fine. Macerate it with the vinegar, 1 tablespoon each of lemon juice and orange juice, and a pinch of salt.
Cut away the grapefruit peel, all the pith below, and the membrane around the grapefruit flesh. Then cut the sections free, carefully slicing along the membranes. Peel a little lemon and orange zest and finely chop enough to make about 1/4 teaspoon of each.
When you are ready to assemble the salad, whisk the olive oil into the shallot mixture. Add the orange and lemon zest and taste. Add more olive oil or lemon juice if necessary. Cut the avocados in half lengthwise. Remove the pits. Using a sharp knife, cut the avocados into lengthwise slices about the same size as the grapefruit sections, keeping the skin on. Scoop out the slices with a large spoon. Toss the curly endive and grapefruit sections in a bowl with about two thirds of the dressing. Taste the salad and add more salt if necessary. Arrange on a platter or individual dishes. Distribute the avocado alongside the endive and grapefruit, season them with a pinch of salt, and drizzle the rest of the dressing over them