In a large mixing bowl, combine the 300 g all-purpose flour and 1/2 tsp salt.
Make a well in the center and crack in the 3 large eggs.
Gradually add 100 ml water while stirring the eggs into the flour with a wooden spoon until you get a thick, sticky dough.
Using a wooden spoon, beat the dough vigorously until bubbles form. This should take about 5-8 min.
The dough should be elastic and smooth but not too runny.
Bring a large pot of salted water to a boil.
Place a spätzle maker or a colander with large holes over the pot.
Push the dough through the holes using a spatula or spoon, so small pieces fall into the boiling water.
When the Spätzle float to the top (after about 2-3 min), they are cooked.
Use a slotted spoon to transfer them to a bowl of cold water to stop the cooking process.
Drain the Spätzle well and heat 1 tbsp butter in a large frying pan.
Add the Spätzle and sauté them until they are lightly golden and slightly crispy on the edges.