Melt the butter in a pan roughly the same size as your tortilla.
In a bowl, whisk the eggs with a pinch of salt and pepper. Pour the eggs into the pan and spread evenly.
Place the tortilla directly on top of the eggs, pressing gently so it sticks to the surface.
Cook for a few minutes until the eggs are set. Carefully flip the tortilla with the egg attached and transfer it to a plate.
Top with spinach, mozzarella, avocado, and tomato.
Fold the tortilla in half, then fold again to form a compact wrap.
Serve immediately while warm.