Preheat oven to 200C. Combine garlic, crème fraîche, thyme and green onion in a saucepan. Cover and cook over low heat for 5 minutes. Set aside.
Place spinach in a large frying pan over medium heat. Stir for about 4-5 minutes until wilted, adding a little water if necessary, Transfer to a colander and press out moisture with the back of a large spoon. Chop finely and reserve until ready to use.
Melt butter in a saucepan over medium heat. Stir in flour. Cook for 2-3 minutes, stirring with a wooden spoon, then add milk and whisk for 2-3 minutes or until thickened. Stir in goat’s cheese and parmesan. Add egg yolks, spinach, garlic, onion and crème fraîche mixture and combine well. Season generously with sea salt and freshly ground white pepper and transfer soufflé mixture to a large bowl.
In another large bowl, whisk egg whites with a pinch of sea salt until they form soft peaks. Add egg whites to the soufflé mix and fold the mixtures together until well combined.
Grease a 6-cup gratin or soufflé dish and spoon soufflé mixture into dish, making sure it is not overfilled. Bake for 40 minutes or until golden brown and set. Serve immediately with a simple green salad.