Bring a large pot of salted water to a boil. Add the gnocchi and cook according to package directions until they float; scoop them out and drain well.

Heat the olive oil in a large skillet over medium heat. Add the minced garlic and sauté for about 30 seconds until fragrant, being careful not to let it brown.

Add the fresh spinach to the skillet and cook, stirring, until just wilted, about 1 to 2 minutes.

Pour in the heavy cream or milk and bring to a gentle simmer. Let it reduce and thicken slightly, about 1 minute.

Stir in the crumbled feta, continuing to stir until the cheese melts into a creamy sauce. If the sauce becomes too thick, add 1 tablespoon of water or milk to loosen it.

Gently fold the cooked gnocchi into the skillet, tossing to coat each piece in the sauce. Cook for another minute so the flavors meld.

Taste and season with salt and pepper as needed. Serve warm and finish with a sprinkle of Parmesan if desired.