Duck Bone Gravy

Duck makes one of the most flavourful stocks going, but it also renders more fat than anything else in the kitchen. Chill it, take the whole lid of fat off and keep it for roast potatoes, then build the gravy on the clean stock underneath. What is left is dark, savoury and slightly sweet.

Ingredients

Makes about 350ml, enough for four with a duck crown

• 2 duck carcasses broken up, plus any wing tips and neck
• 1 onion halved
• 1 carrot
• 1 stick celery
• 3 cloves garlic bashed
• 2 litres (3.5 pints) cold water
• 4 sprigs thyme
• 1 bay leaf
• 4 black peppercorns
• 150ml (5fl oz) red wine
• 2 tsp red wine vinegar
• 20g (0.75oz) plain flour
• 2 tbsp duck fat from the stock
• salt and black pepper

Kit

• Roasting tin
• Saucepan
• Fine sieve
• Jug for defatting

Method

1. Heat the oven to 210C fan (230C conventional, gas 8). Chop the carcasses up with a heavy knife or kitchen shears so they fit in one layer, and roast dry for 40 minutes. Duck skin renders plenty of fat so there is no need to add any oil.

2. Pour the rendered fat off into a bowl halfway through, or the bones will fry rather than roast. Add the onion, carrot, celery and garlic for the last 15 minutes.

3. Move everything to a saucepan. Put the roasting tin over a burner, pour in the red wine and boil it down by half while scraping up the sticky brown residue, then tip that into the pan.

4. Cover with 2 litres of cold water, bring slowly to a simmer and skim. Add the thyme, bay and peppercorns.

5. Hold at a bare tremble for 3 hours. Duck bones are small and give up their flavour quickly, and pushing much past this makes the stock taste slightly livery.

6. Strain and chill for at least four hours. A thick pale cap of duck fat will set on top. Lift it off in one piece and keep it in a jar, because it is the best roast potato fat there is.

7. Reduce the defatted stock in a wide pan from around 1.2 litres to 450ml, roughly 20 minutes. Taste it at this point and you will see how much the reduction has done.

8. Heat 2 tablespoons of the reserved duck fat in a pan, stir in the flour and cook to a light brown roux over 3 minutes. Whisk in the hot stock, simmer for 5 minutes, then add the red wine vinegar. Duck is fatty and slightly sweet and it genuinely needs that sharpness. Season and serve hot.

Tips worth knowing

• Pour the fat off partway through roasting. Bones sitting in deep fat do not brown, they confit, and you lose the colour you are after.
• Duck fat is worth more than the gravy in some households. Strain it through muslin and it keeps six months in the fridge.
• Three hours is enough for duck. Longer stocks go slightly bitter and metallic because the bones are so small and thin.
• If you have the duck's liver, do not put it in the stock. Fry it separately and spread it on toast while you wait.

Keeping and reheating

The stock keeps four days chilled and four months frozen. Finished gravy keeps three days and reheats gently. The rendered fat keeps six months in a sealed jar in the fridge.

Questions people ask