Preheat your oven to 350°F (175°C) and lightly grease an 8x8-inch baking dish.
In a large bowl, whisk together eggs and milk until well combined and slightly frothy.
Add salt, pepper, and oregano (if using) to the egg mixture and stir to incorporate.
Fold in 3/4 cup of the shredded cheese, diced bell pepper, crumbled bacon, green onions, and minced garlic.
Pour the mixture into your prepared baking dish and spread evenly.
Sprinkle the remaining 1/4 cup of cheese over the top.
Bake in the preheated oven for 20-25 minutes, or until the eggs are set and the top is lightly golden.
Remove from oven and let rest for 5 minutes before serving.