Separate the whites and yolks of 2 large eggs. Set the whites aside.
In a large bowl, mash together 4 oz of feta cheese, and 1¾ cup of Greek yogurt until smooth.
Whisk in 2 egg yolks and 5 tablespoons of melted butter until smooth in the feta-yogurt mixture. Set aside.
Whisk together 1 ½ cups of all-purpose flour, ½ teaspoon of table salt, 1½ teaspoons of baking soda, and ½ teaspoon of cracked pepper. Set aside.
Place the egg whites you set aside in the bottom of a stainless steel bowl. Using your stand mixer or hand mixer, whip egg whites until soft peaks form and hold their form, 4-5 minutes.
Fold the flour mixture into the egg yolk mixture being careful not to over-mix.
Gently fold the egg whites into the rest of the mixture in three additions, being careful not to deflate the mixture. The final mixture will be thick.
Heat and grease your waffle iron. When hot, add scoops of waffle batter to your waffle iron and cook until the waffle iron signals they are done, 4-5 minutes. Repeat with the rest of the batter.
Heat a skillet with 1 tablespoon of butter. Once hot, carefully crack eggs into skillet.
Season eggs with salt and pepper.
Fry eggs until whites have set but yolks remain runny, 4 minutes.
Chop green stalks of two scallions. Set aside.
Zest 1 lime and cut into wedges. Set aside.
Half and slice 2 avocados and spritz with lime juice for flavor and to prevent browning. Set aside.
Cube 4 oz of remaining feta. Set aside.
Wash and dry 1 cup of spinach.
Put one waffle on a plate. Add several spinach leaves, a few feta cubes, and slices from ½ an avocado.
Add a fried egg, and top with lime zest, a few scallions, and a few feta cubes.
Add another waffle, and top with a few more feta cubes, scallions, lime zest, and a spritz of lime juice.
Serve immediately.