For the soufflés, preheat the oven to 180C/350F/Gas4.
Brush four ramekins with the melted butter and chill in the fridge for 15 minutes, or until the butter has hardened. Brush with a further coat of butter and chill again.
Meanwhile, heat a frying pan until medium-hot, add 50g/1½oz of the butter and the leeks and sweat over a low heat for 10-15 minutes, or until very soft. Season with salt and freshly ground black pepper.
Melt the remaining 75g/3oz butter in a large saucepan over a medium heat. Add the flour and mix well. Cook the mixture over a low heat for 5-8 minutes, stirring with a wooden spoon.
Gradually whisk in the warm milk, a little at a time, stirring constantly to avoid any lumps forming. Continue until all the milk has been added, then reduce the heat to very low and cook for a further 5-8 minutes.
Remove the mixture from the heat, season with salt and freshly ground black pepper, then strain.
Set aside to cool slightly then add the cooked leeks, cheese, mustard and thyme into the warm mixture. Beat the egg yolks into the mixture and season with salt and freshly ground white pepper.
In a clean, dry bowl, whisk the egg whites until they hold medium peaks then fold the egg whites into the soufflé mixture.
Divide the mixture among the soufflé dishes and put the dishes in a roasting tin. Pour enough boiling water into the tin to reach halfway up the sides of the dishes.
Bake the soufflés for 20-25 minutes, or until they are risen and evenly coloured. Remove the dishes from the tin and set aside for a few minutes.
Run a knife around the edges of the soufflés and turn them out onto individual ovenproof dishes.
For the glaze, preheat the grill to medium-high.
Whisk the cream, parmesan, cheese and egg yolks until combined, then coat the tops of the soufflés with the parmesan glaze. Place under the grill until the tops are golden.
For the salad, preheat a deep-fat fryer to 190C/375F. (CAUTION: hot oil can be dangerous. Do not leave unattended.)
Heat the water and sugar in a saucepan until the sugar has melted and the syrup thickened slightly.
Add the walnuts and cook for 2-3 minutes. Remove the walnuts from the pan and set aside to drain on greaseproof paper.
Carefully place the walnuts, a few at a time, into the deep-fat fryer for a couple of minutes until golden-brown. Set aside to drain from kitchen paper.
Bring a pan of salted water to the boil, add the baby leeks and cook for 1-2 minutes, or until just tender.
Drain and place into a bowl then add the dandelion leaves and walnuts.
Whisk the mustard, vinegar and olive oil together with salt and freshly ground black pepper.
Drizzle a little dressing into the salad and toss well.
To serve, pile the salad onto serving plates and place a soufflé alongside.
Spoon extra dressing around the plate, and serve immediately.