Preheat your oven to 180°C (350°F) and lightly spray your mini muffin tin or small baking dish with non-stick spray or brush with oil.
In a mixing bowl, whisk the egg whites vigorously until they become frothy and slightly opaque, about 30 seconds. This introduces air and helps create a fluffy texture.
Add a pinch of salt and a teaspoon of baking powder to the egg whites, then whisk again to combine evenly. You'll notice the mixture becoming slightly lighter and more voluminous.
Finely chop your chosen vegetables—like spinach, peppers, or herbs—and gently fold them into the egg whites with a silicone spatula, distributing evenly without deflating the mixture.
Pour the egg white mixture into each cup of the prepared muffin tin, filling about three-quarters full to allow room for expansion.
Place the muffin tin in the oven on the middle rack and bake for about 15–18 minutes. You’ll see the edges turn a light golden brown, and the bites will feel set and slightly puffed.
Once baked, remove the tray from the oven and let the bites rest for a few minutes. They will firm up further as they cool slightly.
Gently run a small spatula around the edges of each bite to loosen, then carefully transfer them to a plate or cooling rack.
Serve the egg white bites warm or at room temperature. They’re perfect for breakfast or a quick snack, and can be stored in an airtight container in the fridge for up to two days.
