Wash the radicchio and fennel, cutting them into strips and rounds or small pieces respectively, and dry them thoroughly. Peel the oranges and cut them into slices or small pieces. Prepare the dressing by emulsifying the honey, oil, and balsamic vinegar. Add salt and pepper. Dress the fruit and vegetables with the vinaigrette. Arrange the fennel slices, radicchio, oranges, and chopped walnuts on a plate. Season with salt and pepper. Orange honey is ideal for vinaigrettes.