To prepare spinach, first remove any unwanted stems or brown parts.

Rinse leaves several times in cold water until all the dirt has been rinsed off.

Drain spinach but leave some water clinging to spinach leaves.

Heat a large skillet over medium-high heat and add wet spinach, working in batches if necessary.

Turn spinach frequently with a pair of tongs as it cooks, until it is wilted, about 4 minutes.

Transfer to a strainer and squeeze out as much liquid as possible.

Transfer drained spinach to a cutting board and chop coarsely. Set aside.

Meanwhile, melt butter in a saucepan over medium heat and add garlic and onions.

Cook until onions are translucent and soft, about 10 minutes.

Add cream, parmigiano-reggiano, nutmeg, salt and pepper, and continue cooking until the mixture thickens a bit, about 5 minutes.

Add spinach to cream and mix well.

Continue to cook until cream has almost completely been absorbed and dish is thick and creamy, about 8 minutes.

Remove from heat and serve.