For the al cremat, heat the oil in a lidded frying pan and fry the shallot, anchovy, chilli and garlic for 30 seconds. Stir in the prawns.
Add the wine and stir well. Continue to cook until the volume of the liquid has reduced by three-quarters. Add the fish soup, cover with a lid and cook for three minutes.
Remove the lid and add the parsley and persillade; cover and cook for a further 30 seconds. Set aside.
For the aioli, crush the garlic and salt in a pestle and mortar to a paste. Transfer the mixture to a bowl and whisk in the Dijon mustard. Gradually whisk in the olive oil, a little at a time, until the mixture resembles mayonnaise. Set aside.
For the Little Gem, dandelion and watercress salad, whisk the sherry vinegar, olive oil, Dijon mustard, shallot and salt and freshly ground black pepper in a small bowl. Place the Little Gem lettuce, dandelion, watercress and herbs into a large bowl, pour over the dressing and mix until well combined.
To serve, add the espelette pepper and lemon juice to the aioli and mix until well combined. Spoon into a small bowl.
Spoon the al cremat onto each of two serving plates. Serve the the Little Gem, dandelion and watercress salad, aioli and toast alongside.