Combine all the galette ingredients in a bowl and whisk until the batter is smooth
Place the galette batter in the fridge for at least one hour. (Note 1)
Place a frying pan or galette pan on a medium to high heat and add no more than 1 teaspoon of butter to grease the pan.
When the pan is hot add a ladleful of the galette mixture and spread evenly over the pan. (Note 2)
When the galette starts to set crack the egg onto the batter and adjust the position of the egg so it sits in the centre if necessary.
Add the spinach and cheese so they surround the egg.
Leave the galette to cook on a medium to high heat until the egg starts to set.
Add a tiny pinch of salt to the egg yolk and season the galette filling with ground nutmeg and ground black pepper.
Increase the heat to crisp up the galette and cook on a high heat for a few minutes until you see the sides start to brown. Lift up the sides to check they are done.
When the galette is crisp fold the sides into the middle and serve. The folds should be no more than 2 inches so the egg is visible
Repeat steps 4-10 with the rest of the galette batter