Mix the garlic and yoghurt in a small dish; season with salt and pepper. Dip each mushroom into the yoghurt mixture, covering fully. Coat in breadcrumbs and place the mushrooms on a non-stick baking tray.
Bake in the preheated oven until the mushrooms are tender, 10 to 15 minutes.
Serve with remaining yoghurt.
It is best to prepare the yoghurt mix the day before to develop flavour.