Preheat your oven to 400 degrees.
Crack your eggs into a large bowl, add the water and whisk until all combined.
Heat your butter in an oven safe 12” non-stick skillet over medium high heat. Once the butter is melted, add your spinach with a pinch of salt and pepper. Cook until the spinach has all wilted down. This will take approximately 4 minutes. Shut off the heat and move the pan off the burner.
Now, add your eggs to the skillet along with the salt and black pepper. Give this a stir with a spatula. Top with your goat cheese by breaking into little pieces and distributing evenly over the frittata. Now, spread your sun-dried tomatoes evenly around the frittata.
Place in the oven for 13-15 minutes. You just want to make sure that all the eggs have been cooked. You can tell by there being no liquid on top. Carefully remove from the oven and serve.