To cook the eggs en cocotte, reduce the oven temperature ... remove the thyme and bay, then crack in a duck egg and top with the remaining sauce. Bake for 3 minutes, or until the whites have ...

A Waitrose spokesman said fertilised eggs were safe to eat and "entirely ... "There may also be instances when a wild duck encounters farmed drakes, but again, this is rare," he said.

But chicken eggs aren't the only eggs around — and it may be worth giving duck eggs a try once in a while, too. "We certainly ...