Clean the fennel and put some green aside. Wash the fennel and slice finely. Peel 2 oranges so that the white skin is completely removed. Cut the fruit into thin slices. Peel onions and cut into fine rings. Halve 1 orange and squeeze the juice. Mix vinegar and orange juice, season with salt, pepper and sugar.
Whip oil into it. Chop the nuts and stir into the vinaigrette. Arrange fennel, oranges and onions on a plate, pour some vinaigrette over them. Serve the rest separately. Garnish with fennel greens. Delicious with baguette