Ingredients

Step by step

1. To make the mushroom ketchup, heat a splash of the oil in a large pan over a medium heat, add the onion and a pinch of salt and gently sweat for 8-10 minutes until translucent.
2. Finely chop the chestnut and large flat mushrooms, then add to the pan with a splash more oil. Cook down until soft. Meanwhile, boil a kettle and pour 150ml boiled water over the dried mushrooms in a bowl and leave to soak for about 5 minutes, or until softened. Drain, reserving the mushroom liquid, and add the rehydrated mushrooms to the pan.
3. Add the nutmeg, mace and garlic granules to the pan, stir for 30 seconds, then add the rest of the ingredients, including the mushroom liquid. Simmer over a low heat for 10 minutes, stirring occasionally.
4. Transfer to a blender and blitz until smooth, then taste and adjust the seasoning if necessary. Add a splash of water if you want to loosen the consistency. Allow to cool, or chill if making ahead.
5. Boil the sprouts in salted water for 4-5 minutes until tender. Refresh in cold water and dry well (this is important, as you will be adding them to hot fat).
6. When ready to serve, put the duck fat into a small-medium saucepan and heat to 180°C (check with a thermometer or drop in a cube of bread – it should take about 15 seconds to brown). Add the sprouts in batches and fry until crispy all over. Use a slotted spoon to transfer to a kitchen paper-lined plate and repeat with the remaining sprouts. Season with salt, then serve with the mushroom ketchup. The duck fat can be cooled and re-used to cook Yorkshire puddings or roast potatoes.