In a large skillet, heat the olive oil over medium heat. Add the diced onion and kosher salt, sauté for about 5 minutes until translucent. Add minced garlic and dried thyme, cook for an additional minute.
Add unsalted butter to the skillet and let it melt. Sprinkle in all-purpose flour, stirring continuously for about 1 minute. Gradually whisk in whole milk, ensuring no lumps. Whisk until sauce thickens, about 3-5 minutes. Stir in ground nutmeg.
Bring a large pot of salted water to boil. Add dried gnocchi and cook according to package instructions until they float, about 2-4 minutes.
Once the gnocchi are cooked, drain them and add directly to the skillet with the sauce. Stir gently to coat the gnocchi in the creamy mixture.
Toss in fresh spinach and grated Parmesan cheese. Stir until spinach wilts and cheese melts. Squeeze in lemon juice and adjust seasoning with salt and pepper.
Serve hot, garnished with additional Parmesan if desired. Enjoy!
