Preheat your oven to 375 degrees f. and lightly spray 4 single serving baking dishes with avocado cooking oil spray.
Melt the butter in a large skillet over medium heat. Add in the spinach and cook, stirring continuously until wilted, around 2 minutes.
Meanwhile, in a small bowl, whisk your milk with Arrowroot powder/flour until smooth.
Once the spinach is wilted, stir in your milk mixture together with the garlic and parmesan cheese.
Stir well and continously to combine while still on the medium heat. The spinach will get incredibly creamy in about 2 minutes. Remove from heat and divide spinach mixture equally among your 4 baking dishes.
Crack an egg into each dish, then sprinkle with more parmesan cheese if desired.
Bake in your preheated oven for 12-15 minutes, or until the eggs are set to your liking.
Sprinkle with microgreens or fresh herbs if desired
Enjoy while hot.