Preheat your oven to 350°F (175°C) and prepare a muffin tin by spraying it with cooking spray or lining it with muffin liners to ensure easy removal.
Whisk the egg whites in a bowl with a pinch of salt and pepper until the mixture is frothy, which helps to introduce air and creates a light texture in the bites.
Fold in the veggies (½ cup diced veggies of your choice), cheese (½ cup shredded cheese), and your choice of cooked meat (½ cup of turkey bacon or cooked chicken) if using. Make sure to mix gently to maintain the airiness of the egg whites.
Fill the muffin cups about ¾ full with the egg mixture. This provides room for the bites to rise slightly while baking.
Bake in the preheated oven for 20-25 minutes or until the tops are golden and set. Insert a toothpick into the center of one of the bites to check for doneness; it should come out clean.
Cool slightly before serving warm, or let them cool completely before storing for later use. Enjoy your nutritious bites!