I Make These Rustic Italian Dumplings Whenever I Want Something Warm and Hearty

Name: I Make These Rustic Italian Dumplings Whenever I Want Something Warm and Hearty
Ingredients: 1 stick plus 2 tablespoons (140 g) unsalted butter, divided; 1 medium clove garlic, lightly smashed; 1 3/4 pounds (793 g) mature spinach, well washed and stem ends trimmed if necessary (see notes); Kosher salt; 1/2 cup breadcrumbs (2 3/4 ounces; 75 g); 1 packed cup finely grated Grana Padano or Parmigiano-Reggiano (4 ounces; 113 g), plus more for serving; 2 large eggs; Freshly grated nutmeg; Freshly ground black pepper; Small handful (about 10) fresh sage leaves