Bring a large pot of salted water to a boil. Add the gnocchi and cook according to package instructions until they float to the surface, usually about 2-3 minutes. Use a slotted spoon to remove the gnocchi and set them aside to drain.
In a large frying pan, heat the olive oil over medium-high heat. Once hot, add the cooked gnocchi and cook undisturbed for about 2-3 minutes until they become golden brown and crispy on one side.
Gently stir the gnocchi and cook for another 2-3 minutes, ensuring they get crispy on all sides.
Reduce the heat to medium and add the minced garlic to the pan. Sauté for about 1 minute until fragrant, being careful not to burn it.
Add the fresh spinach to the pan, stirring gently until it wilts, which takes about 2-3 minutes.
Season the mixture with salt, black pepper, and red pepper flakes (if using). Remove from heat.
Stir in the crumbled feta cheese, allowing it to combine with the other ingredients. Serve immediately on plates.