Heat oven to 350 deg F.

Heat butter and olive oil and cook the leeks with salt for about 6 mins. Transfer to cool.

Whisk the eggs with 1/2 tsp salt and several grinds of pepper. Add the leeks, thyme and goat cheese and gently stir to combine.

10 in oven proof dish for 15-20 mins. Let cool for 2 mins.