Preheat oven to 375 F.
In a bowl, whisk the eggs and season to taste.
10 to 12 eggs, Sea salt and freshly ground black pepper to taste
Melt the ghee in an oven-safe skillet over medium heat.
2 tbsp. ghee
Add the garlic and onion, and cook until soft, 2 to 3 minutes.
2 garlic cloves, 1 small onion
Add half of the sliced tomatoes, all of the crumbled bacon, and spinach; cook another 2 to 3 minutes or until the tomato is soft.
4 oz. baby spinach leaves, 2 tomatoes, 5 bacon slices
Pour the eggs into the skillet. Cook until it starts to set just a little, then place the remaining tomatoes on top.
Transfer the skillet to the oven and bake for 15 to 20 minutes or until the frittata is fully set.