Wash the potatoes and cook for about 20 minutes. Wash the chicken fillets, dab dry and cut in half. Fry in 2 tablespoons of hot oil for 15-20 minutes. Turn several times in between. Season with salt and pepper.
In the meantime, wash the tomatoes, dab dry and cut in half or quarters. Wash the sprouts and let them drip off. Clean the frisée, wash and also drain. Drain the potatoes, rinse with cold water and let them cool down a bit. Peel and cut into slices. Remove meat from the pan and cut into slices. Add remaining oil and vinegar to the frying oil and mix. Add mustard. Season to taste with salt and pepper.
Remove meat from the pan and cut into slices. Add remaining oil and vinegar to the frying oil and mix. Add mustard. Season to taste with salt and pepper. Mix potato slices, tomatoes, sprouts and frisée with the vinaigrette. Arrange the chicken meat on the salad