In a bowl, mix both kinds of flour quickly with the eggs, milk, salt, and mace until a firm dough forms.
Fill a large pot with water, bring it to a boil, and add two or three pinches of salt. Using a spaetzle maker or patato ricer and working in batches, drop the dough into the boiling water, and allow to simmer at low heat for 2-3 minutes. The spaetzle are done when they float to the top.
Drain the spaetzle in a colander. When you have cooked all of the spaetzle, melt 40g / 4 tbsp of the butter in a pan, add the spaetzle, and sprinkle the cheese on top. Stir well and cook at low heat for 2-3 minutes until the cheese has melted.
Peel the onions, and slice into thin rings. In another pan, melt the rest of the butter, add the peeled garlic clove and the onions, and cook until golden brown. Remove the garlic bevore serving.
Out tips:
Spaetzle are the perfect family meal. You can also bake them as a casserole: butter a baking dish, put a layers of the spaetzle, onions, and cheese, and bake at 140C / 300F for 15-20 minutes. Serve family-style with a green salad.
For a more authentic recipe, substitute one cup of Emmental cheese with German Bergkäse, a hard “mountain cheese” made of raw milk.