Cut chicken fillet into large pieces, bake or fry in a pan. Cool down and cut into thin long slices.
Cut pears into thin slices. Break walnuts coarsely. Melt butter in a frying pan, add sugar, 1 tablespoon of balsamic vinegar, stir and fry pears on both sides for 2-3 minutes. Add walnuts 2 minutes before the end. Cool down.
Mix amaranth oil, Dijon mustard and 1 teaspoon of balsamic vinegar.
Place arugula and spinach, tomatoes cut in half, caramelized pears and walnuts, and chicken fillet onto a plate. Season with the prepared sauce.