Put the butter in a pan and stir until melted, add the garlic and the onion and sauté lightly. Add the carrot, the red pepper, the green pepper, mix lightly and add salt and black pepper, mix well until sautéd.
Set aside into a bowl.
In another bowl, put the eggs, the milk, a generous pinch of black pepper and 1 teaspoon of salt, whisk very well until combined, add the Parmesan cheese, whisk very well again.
Transfer this egg mixture to the bowl with the vegetables and mix well.
Grease a cupcake baking tray with olive oil, or if you prefer, you can grease with butter and wheat flour.
Pour some of this mixture into each hole, distributing evenly.
Bake in a preheated oven at 200°C (392°F) for 15 to 20 minutes.
Baking time may vary depending on the power of your oven!
Serve.