Slit the chilli pepper lengthwise, remove the core and white dividers, then finely chop the pepper.
Stir the chopped chilli and cornstarch into the quark mixture, then season with salt and cayenne pepper to taste.
Using a teaspoon, cut off a small piece of the quark mixture directly into gently simmering salted water as a test. Cook for 3 to 4 minutes (do not let the water boil) until the dumpling floats to the surface. Remove with a slotted spoon, drain, and taste to check the flavor and texture.
Using a teaspoon, cut off the remaining quark mixture directly into the gently simmering salted water. Cook for 3 to 4 minutes (do not let the water boil) until they float to the surface. Remove with a slotted spoon and drain.
Serve the dumplings in pea and coconut soup, tomato soup, broccoli soup, or another soup of your choice.