Leeks with parmesan, brie and cheddar

Ingredients:

- 5-6 leeks

- 50 g parmesan

- 100 g brie cheese

- 100 g cheddar

- 100 g single cream

- 2-3 tablespoons thyme

- 50 g unsalted butter

- two cloves of garlic

- extra virgin olive oil.