PREPARATION

1. Preheat the oven to 190C. Line a tart pan with parchment paper and the quiche dough. Place another piece of parchment paper on top and fill with baking beans (these can be dried chickpeas, black beans, etc., and can be re-used).
2. Bake the quiche "blind" for 15 minutes. Then, remove the beans and parchment paper and bake the crust for an additional 15/20 minutes until it turns golden brown.
3. Meanwhile, thinly slice the leek. Heat a dash of olive oil in a skillet and sauté the leek with thyme and chopped garlic until soft and translucent.
4. Tear or slice the mushrooms into pieces and sauté them in two batches in a single layer in the pan over high heat with a dash of olive oil until cooked and golden brown. Set aside some slices of king oyster mushrooms for the topping.
5. Beat the eggs, grate the cheese, and add them to the eggs along with the heavy cream, salt, pepper, leek, and mushrooms.
6. Poke some holes in the bottom of the baked quiche crust with a fork, then pour the quiche filling into the pan, topping it with the set-aside king oyster mushrooms. Bake the quiche for 35-45 minutes until it is cooked and golden brown.
7. You can serve the quiche warm or cold.