Preheat oven to 350°F. Grease a 9x13-inch baking dish.

Cook bacon in a skillet until crispy. Set aside on a paper towel-lined plate.

Sauté onion, red bell pepper, and garlic in the same skillet until softened.

In a large bowl, whisk eggs and milk. Stir in cooked vegetables, potatoes, 1 cup cheese, and most of the bacon. Season with salt and pepper.

Pour mixture into prepared baking dish. Sprinkle remaining cheese on top.

Bake for 20 minutes. Add reserved bacon and green onions, then bake for another 20–30 minutes until eggs are set and golden brown.

Let cool for 10 minutes before slicing. Serve warm.