Preheat oven to 350°F/ 180ºC.

In a bowl, beat the eggs with the milk and season with a pinch of salt and pepper.

Heat a small amount of oil in a pan over medium heat, add onions and saute until brown.

Add the kale to the pan and stir it through so it wilts, just cook for 1 minute.

Mix the onion and kale in with the beaten egg mixture.

Lightly grease 4 muffin cups with olive oil.

Spoon or carefully pour the mixture evenly into the muffin cups.

Place 3-4 halved tomatoes on top of each one.

Bake for 20-25 minutes or until brown on top and puffy.

Allow to cool for a few minutes before eating, or eat them cold if preferred.