Mix the flour with 1 teaspoon salt in a bowl. Add eggs and approx. 200 ml water. Beat everything vigorously to form a smooth dough. The dough should flow tough from the spoon or hook of the food processor.
Coarsely grate both types of cheese. Bring the salted water to the boil in a large saucepan. Put the dough in portions in a spaetzle press. Press into the water and cook for 2-3 minutes. Lift out with a slotted spoon and drain in a sieve. Remove some of the cooking water. Put the hot spaetzle with the removed cooking water in a preheated bowl. Scatter cheese on top and mix everything carefully. Season with pepper.
Peel the onions and cut into thin rings. Heat the clarified butter in a large pan and slowly fry the onions until brown. Finally dust with paprika and fry briefly. Wash the chives, shake dry, cut into rolls. Sprinkle onions and chives over the cheese spaetzle and serve immediately.