Preheat the oven to 180°C/fan 160°C/gas mark 4. Brush the insides of 8cm soufflé moulds with the melted butter. Mix the breadcrumbs and crushed walnuts together and put a heaped tablespoon in each of the moulds. Gently shake and move each mould around to coat the whole of the inside with the mixture and set aside in the fridge.
Place 300ml of the milk, the onion, bay leaf and cloves in a medium-sized saucepan and warm through. Do not let the milk boil.
Place the butter in another medium saucepan and melt over a medium heat, then add the flour, stir and cook for 4 minutes until the raw taste of the flour has gone. This is your roux. Gradually strain the warm milk into the roux while it is still on the heat, throwing away the aromatics left in the sieve, and whisking all the time. Add the soft goat’s cheese and stir, then remove one quarter of the sauce to a small saucepan and set aside to cool for 10 minutes.
Stir the egg yolks into the sauce in the medium-sized saucepan, then add the nutmeg and seasoning. Transfer the mix to a bowl. In a separate bowl whisk the egg whites until firm. Off the heat, roughly fold in one tablespoon of the egg whites into the sauce, then gently fold in the rest, keeping the mixture airy.
Fill the moulds to the top with the mixture and run your finger around the edge to clean the lip – this will help the soufflés rise. Add the fingers of hard goat’s cheese in the centre of each soufflé. Place the filled moulds in an oven dish and pour boiling water into the dish to a level halfway up the sides of the moulds - this is a bain-marie. Cook in the oven for 20 minutes.
Meanwhile plunge the whole trimmed leeks into boiling salted water and cook for 3 minutes until soft. Remove and slice the green part into thin rounds. Put the small saucepan that was set aside with the cooled sauce back on a low heat. Add the remaining 100ml of milk to make a thinner sauce. Then add the chives and keep warm until heated through.
Remove the soufflés from the oven and turn the oven up to 200°C/fan 180°C/gas mark 6. Use a knife to loosen the edges of the soufflés, then tip them out on to a baking tray lined with greaseproof paper and place back in the oven for 5 minutes.
Place 6 thin leek rounds in a circle on each plate. Place a soufflé on top of the leeks, drizzle with the remaining goat’s cheese sauce and scatter the walnuts over.