Line a large baking tray with baking paper. Bring a large saucepan of water to the boil. Add one-quarter of gnocchi. Cook for 2-3 mins or until the gnocchi rise to surface of the pan. Use a slotted spoon to transfer to lined tray. Repeat, in 3 batches, with remaining gnocchi.
Meanwhile, melt the butter in a large frying pan over medium heat. Cook for 2-3 mins or until the butter melts and begins to foam. Add the sage and cook for 1-2 mins or until crisp. Use a slotted spoon to transfer the sage to a plate.
Add the garlic, gnocchi and spinach to the pan. Season. Cook, tossing, until the gnocchi is coated in butter mixture and the spinach wilts.
Divide the gnocchi mixture among serving bowls. Sprinkle with fried sage and walnuts. Sprinkle with parmesan.
