Pre-heat the oven to 180C, gas mark 4 and put a kettle on to boil.
Gently steam the leeks with some seasoning in its own juices in a small pan with a lid for 5 minutes.
Divide the cooked leek between the ramekins and place them in the roasting tin then break an egg into each ramekin, add some more seasoning, then put a tablespoon of double cream or crème fraîche on top of each yolk.
Place the roasting tin on the centre shelf of the oven and pour enough hot water, from the kettle, into the tin to come halfway up the sides of the dishes.
Now let the eggs bake for 15 minutes if you like them soft and runny, or 18 minutes if you like them more set.
Either way, bear in mind that they go on cooking in the dishes as they leave the oven and reach the table.