What is
Quark is a type of fresh dairy product, common for the cuisines of German-speaking countries made by warming soured milk until the desired degree of coagulation (denaturation, curdling) of milk proteins is met, and then strained.
Junket is a milk-based dessert, made with sweetened milk and rennet, the digestive enzyme which curdles milk. It might best be described as a custard or a very soft, sweetened cheese.