Combine the eggs, milk, flour, sugar, salt and 2 tablespoons of melted butter in a blender or a large bowl. Either blend it or whisk it until smooth and creamy. (I didn't have milk, so I used half cream and half water and it turned out great) If you're just making crepes with fruit, you can add 1 tsp. vanilla to the crepes, and a tablespoon of sugar.
Set the crepe mixture aside and saute the spinach in olive oil until wilted. Set it aside in a pan so it stays warm. Clean and slice the mushrooms, then saute them in a large skillet with the butter until they are tender - about five to 10 minutes.
When mushrooms are finished, set them aside (or add them to the spinach pan) to stay warm.
In a separate wide bottomed, non-stick skillet, melt 1 Tablespoon of butter and pour about a half cup of batter. Roll pan from side to side so the batter covers the bottom of the pan. Cook about 1 minute, until just starting to lightly brown and flip over, cooking one more minute. Place on a separate plate and fill with spinach and mushroom mixture. Set it aside, keeping it warm.
In a separate pan, fry an egg in olive oil over medium heat, turning until very lightly cooked on both sides. Place egg on top of spinach, mushroom mixture and fold crepe over edges. Serve immediately. This should make about five crepes filled with mushrooms and spinach.