Remove avocados from the skin, mash with lime juice and mix well with the quark. Season with salt and pepper.
Boil potatoes al dente, then rinse with cold water.
Wash peppers and cut into 2x2cm pieces. Clean the mushrooms.
Peel potatoes, halve and stuck alternately with mushrooms and peppers on skewers. Season with salt and pepper.
Season chicken fillets with salt and pepper and grill with skewers over medium heat.
Cut fillets into slices and serve with the skewers and the dip.