Spätzle with cheese and onions

Spätzle is the German form of pasta from Swabia, a region of southern Germany. It’s important to get the consistency of the dough right and to beat some air into it: you’ll see bubbles coming up when it’s ready. Traditionally, the dough is smoothed out thinly on a wooden board using the hands and then chopped into thin strips with a knife, but it’s easier to use a potato ricer.