1. Preheat the oven to 180°C (350°F).
2. Heat the milk in a bowl in the microwave. Add the oatmeal flakes and let them soak for 10 minutes.
3. Drain the mushrooms. Peel and finely chop the garlic. Heat the oil in a non-stick pan, then add the mushrooms and garlic. Cook for about 10 minutes over low/medium heat until they have released their water.
4. In a bowl, mix the eggs, cheese, parsley, chives, nutmeg, salt, and pepper. Add the oatmeal flakes, then the mushrooms.
5. Mix well and pour into silicone tartlet molds or molds lined with parchment paper. Bake for 30 minutes.
6. When serving, garnish each mini quiche with a spoonful of Greek yogurt and serve with a salad!