Begin by preheating your oven to 350°F (175°C). Grease a standard muffin tin with cooking spray or lightly coat it with oil.
In a large mixing bowl, crack all 6 eggs and whisk them vigorously until well combined and a light froth forms.
To the egg mixture, add the milk, garlic powder, onion powder, and a pinch of salt and pepper. Whisk again until everything is fully incorporated and the mixture is smooth.
Gently fold in the finely chopped spinach and the crumbled feta cheese until evenly distributed. If you are using them, incorporate the halved cherry tomatoes at this stage.
Carefully pour the egg mixture into each muffin cup, filling them about three-quarters full.
Place the muffin tin in the preheated oven and bake for 18-20 minutes or until the egg bites are firm in the center and the edges appear slightly golden brown.
Once baked, remove the muffin tin from the oven and let the egg bites cool for about 5 minutes. Carefully run a knife around the edges of each bite to assist with removal, then gently lift them out.
Notes
Arrange the egg bites on a vibrant platter and sprinkle with freshly chopped herbs for presentation.