Follow these steps to create the perfect egg white bites:

1. Preheat the oven: Start by preheating your oven to 350°F (175°C). Lightly grease a 12-cup muffin tin with cooking spray or a small amount of oil to ensure the egg bites release easily.
2. Prepare the vegetables: Wash and dice your bell peppers, spinach, and red onions into small, uniform pieces. This helps them cook evenly and blend well into the egg whites.
3. Whisk the egg whites: In a large mixing bowl, whisk the egg whites with salt, pepper, and garlic powder until they’re frothy. This step helps to create a light and airy texture for the bites.
4. Assemble the bites: Evenly distribute the diced vegetables into the greased muffin tin cups, filling each cup about halfway. If using cheese or turkey bacon, add them on top of the vegetables.
5. Add egg whites: Carefully pour the whisked egg whites into each muffin cup, filling them almost to the top. Be careful not to overfill, as the egg whites will expand slightly as they bake.
6. Bake: Place the muffin tin in the preheated oven and bake for 18–20 minutes, or until the egg whites are set and no longer jiggle in the center.
7. Cool and serve: Remove the bites from the oven and let them cool for 5 minutes before using a butter knife or spatula to gently release them from the tin. Serve warm or store for later!