- 4 large baking potatoes
- 25g/1oz butter
- 3 free-range eggs, yolks only
- salt and freshly ground black pepper
- 1litre/1¾ pints fish stock
- 1kg/2lb 2oz monkfish fillet, cut into large chunks
- 25g/1oz butter, plus extra for frying
- 25g/1oz plain flour
- 110g/4oz baby onions peeled
- 110g/4oz button mushrooms, quartered
- 4 free-range eggs, yolks only
- 250ml/9fl oz double cream
- 3 tbsp tarragon leaves
- For the potatoes, preheat the oven to 200C/400F/Gas 6.
- Bake the potatoes in the oven for about 1 hour 15 mins until tender when pierced by a knife.
- Remove and cool enough to handle then scoop out the flesh and pass through a fine sieve into a bowl.
- Beat to a smooth and fluffy purée then add the butter and egg yolks. Season to taste with salt and freshly ground black pepper.
- Spoon into a piping bag then pipe little pyramids onto a baking tray and place in the oven for 5-10 minutes until golden-brown.
- For the blanquette, put the fish stock into a large sauté pan and bring to a gentle simmer.
- Add the monkfish and return to a simmer, then poach for five minutes until just cooked through. Remove from the stock and set aside.
- Heat a heavy-based saucepan over a medium heat. Add the butter and melt, then add the flour and keep stirring until it is completely absorbed.
- Gradually whisk in the fish stock, and keep stirring until all the stock has been added.
- Heat a frying pan over a medium heat, add a little more of the butter and the onions and cook until coloured slightly then add the mushrooms and cook for a further two minutes then tip into the fish sauce.
- Return the monkfish to the sauce and bring to a simmer.
- Whisk the egg yolks and cream together in a bowl then gradually add to the fish sauce, whisking as you go.
- Remove from the heat and continue to whisk for a couple of minutes. Stir in the tarragon and check the seasoning.
- To serve, place a couple duchess potatoes onto each plate. Spoon the blanquette alongside and finish with a little more tarragon.