Preheat your oven to 180°C (350°F) and lightly spray a muffin tin with non-stick spray or brush with olive oil to prevent sticking.
Pour the egg whites into a mixing bowl and whisk vigorously for about 30 seconds until frothy and shiny. This introduces air and creates a light texture.
Add a pinch of salt and your chopped herbs to the egg whites, then give it a gentle whisk to combine everything evenly.
Gently fold in shredded cheese and sautéed vegetables into the egg mixture, being careful not to deflate the foam.
Pour the mixture evenly into the prepared muffin tin cavities, filling each about three-quarters full to allow for puffing.
Place the muffin tin on a baking sheet for stability and bake in the preheated oven for 15–18 minutes, until the bites are golden and puffed slightly.
Check the bites—they should be golden on top, slightly puffed, and smell faintly toasted. Gently jiggle the pan; they should wobble just a little but hold their shape.
Remove from the oven and let the bites rest for 2–3 minutes; they will set and become easier to serve.
Use a small spatula or butter knife to loosen the edges gently, then transfer the bites to a plate. Garnish with extra herbs if desired.
Enjoy your fluffy, nutritious egg white bites warm or at room temperature as a quick snack or light meal.