Equipment
* optional
Ingredients
Spaetzle Batter
- 300 g all-purpose flour
- 4 large eggs, room temperature
- 120 ml whole milk
- 5 g kosher salt
- 1 g ground nutmeg
Mix-ins
- 30 g unsalted butter
- 2 yellow onions, thinly sliced
- 350 g kielbasa, sliced into half-moons
Cheese and Garnish
- 250 g gruyere cheese, freshly grated
- 5 g fresh chives, finely chopped
Nutrition (per serving)
Method
Melt the unsalted butter in a large skillet over medium-low heat. Add the sliced yellow onions and cook slowly, stirring occasionally, until deeply caramelized and sweet, about 25 minutes. Transfer to a bowl and set aside.
In the same skillet, increase the heat to medium-high. Add the sliced kielbasa and sear until the fat has rendered and the edges are well browned and crispy, about 7 minutes. Remove from the heat.
In a mixing bowl, vigorously whisk together the flour, eggs, milk, kosher salt, and ground nutmeg until a thick, stretchy dough forms and bubbles appear on the surface.
Bring a large pot of heavily salted water to a rolling boil. Working in batches, press the batter through a spaetzle maker or a colander with large holes directly into the boiling water. Cook until the dumplings float to the surface, about 2 minutes. Remove with a slotted spoon and drain well.
Preheat the oven to 200°C/400°F. Lightly grease a 9x13 inch baking dish.
Spread half of the drained spaetzle evenly into the prepared baking dish. Top with half of the caramelized onions, half of the seared kielbasa, and half of the grated gruyere cheese. Repeat with a second layer, finishing with a generous, even layer of cheese.
Bake in the preheated oven at 200°C/400°F until the cheese is bubbling, thoroughly melted, and beginning to brown on the edges, about 15 to 20 minutes.
Remove the baking dish from the oven and let the casserole rest for 5 minutes. Scatter the finely chopped fresh chives evenly over the top before serving.
Chef's Notes
- For the best texture, the spaetzle batter must be beaten vigorously. This specific action develops the gluten just enough to give the dumplings their characteristic chew without making them tough.
- Always take the time to grate the Gruyere cheese from a solid block. Pre-shredded cheeses are coated with cellulose and anti-caking agents that will prevent the cheese from melting into a smooth, cohesive blanket.
- Do not rush the onions. Proper caramelization requires patience over moderate heat to slowly coax out the natural sugars without burning. This sweet element provides a crucial counterbalance to the intensely savory, salty kielbasa.
- Be generous when salting the boiling water for the spaetzle. The dumplings cook very quickly and the cooking water is your only opportunity to season the interior of the dough.
Storage
Refrigerator: 4 days — Store tightly covered in an airtight container to prevent the cheese from drying out.
Freezer: 1 month — Thaw overnight in the refrigerator before reheating. The spaetzle texture may soften slightly.
Reheating: Cover tightly with foil and bake at 175°C/350°F until heated completely through, or microwave individual portions on medium power.
