Prepare the Oven: Set your oven temperature to 350°F (175°C) to warm it up. Lightly spray a 6-cup muffin tin with cooking oil to prevent sticking.

Prepare the Vegetables: Finely chop your choice of vegetables. Make sure to pat them dry with a paper towel if they are particularly moist, such as tomatoes or mushrooms. This helps prevent excess moisture in the muffins.

Mix the Egg Mixture: In a medium bowl, crack the eggs and whisk them together until well combined. Add the salt, black pepper, and chopped fresh herbs, and mix well.

Assemble the Muffins: Evenly distribute the chopped vegetables among the muffin cups. Sprinkle crumbled feta cheese and chopped green onion over the vegetables in each cup.

Pour the Eggs: Carefully pour the egg mixture over the vegetables and cheese in each muffin cup, filling them about ¾ of the way full. The muffins will puff up as they bake.

Bake: Place the muffin tin in the preheated oven and bake for 18-20 minutes, or until the eggs are set and the tops are lightly golden.

Cool and Serve: Remove the muffins from the oven and allow them to cool in the tin for a few minutes. Use a small spatula or knife to loosen the edges and carefully remove the muffins from the tin. Serve warm or at room temperature.