In a bowl, beat the eggs and then add the feta cheese, mushrooms, and garlic and mix well. Put this mixture in a preheated, greased small skillet. You want to use a small skillet, like an omlette skillet so the mixture cooks thick. Cover and let cook on medium to medium-high heat.
Meanwhile, cut your bagels and toast them. Add cream cheese to your liking.
Check on the eggs. The egg mixture is pretty thick, so I've found I've needed to lift the edges to let the runny stuff flow underneath to make sure the entire thing cooks through. Once the bottom side starts getting brown, use a spatual and flip the entire thing over. You may need to use two spatulas, but I was able to flip mine with little difficulty. Cover and cook the other side.
Once egg mixture is fully cooked, remove from skillet and cut in pieces. Place stategically on bagels and cut in half. Serve while warm. Enjoy!