Sauté the onion in a pan with a splash of Robust EVOO. When it starts to brown, add the balsamic vinegar and the sugar and stir. Cook the mixture over low heat until it forms a thick sauce. Set it aside.
2.
Cook the diced chicken breast on a very hot griddle. Season with salt and pepper and add a pinch of fresh rosemary.
3.
Combine the chopped frisée, the sliced olives and the diced feta in a bowl.
4.
Add the chicken breast (warm or cooled, depending on your preference).
5.
For the vinaigrette, mix all the ingredients together, pour it over the salad and toss.