Most flounder, whether it be the winter or summer variety, is sold filleted. But cooking it whole, as in this recipe ... white and pulls away from the bones, about 18–20 minutes.

Instead, buy flounder from March to November. To cook whole flounders, trim away the fins, head and blood-line, then grill or bake whole with citrus, herbs and butter as you would cook turbot.

For more recipes with good sources of vitamin D, check out: Prawn omelette Calves' or lambs' liver salad Winter salmon and mushrooms Lightly dredge a whole flounder in well-seasoned flour.