For the brine, toast the peppercorns and fennel seeds in a large pot over a high heat for 1 minute, then add the apple juice, sea salt, thyme and bay leaves. Crumble in the dried chillies and bring to the boil, then turn the heat off, top up with 1 litre of cold water and leave to cool. Use a sharp knife to carefully cut down the back of the chicken so you can open it out flat, then add to the cooled brine (transfer to a bigger container, if needed). Cover and refrigerate for at least 12 hours, then drain and pat dry with kitchen paper. Preheat the oven to 200ºC/400ºF/gas 6. Roughly tear the sourdough into big chunks, break up the garlic bulb, and put aside. Rub 1 tablespoon of olive oil all over the chicken and place it directly on the bars of the oven, skin side up, with a large tray underneath to catch the juices. Roast for 30 minutes, then reduce the temperature to 160ºC/325ºF/gas 3. Add the sourdough and unpeeled garlic cloves to the tray and carefully toss to coat in the juices. Roast for 1 hour, or until the chicken is golden and cooked through, tossing the croutons occasionally. Leave the chicken to rest for 30 minutes before carving. Meanwhile, drain the anchovies (saving the oil) and halve lengthways, then arrange on a plate in a criss-cross fashion. Finely chop the parsley stalks (reserving the leaves), finely slice or chop the chillies, and scatter both over the anchovies. Drizzle over ½ a tablespoon each of the reserved anchovy oil and extra virgin olive oil, then finely grate over half the lemon zest and squeeze over half the juice. Leave to marinate. For the Caesar dressing, finely grate the Parmesan into a bowl, add the mustard, Worcestershire sauce and yoghurt, and whisk to combine. Squeeze in the lemon juice, add 8 tablespoons of extra virgin olive oil and mix again. Taste and season to perfection, loosening with a splash of water, if needed. Trim the lettuces and radishes and scrape a fork down the sides of the cucumber. Finely slice the radishes, cucumber, parsley leaves and chives, roughly chop the lettuces, and place everything in a large bowl. Add half the croutons to the salad, pour over half the dressing and toss together, then use a speed-peeler to shave over a little Parmesan. Arrange the chicken and remaining croutons on a board, then serve it all up with the anchovies and extra dressing. Let everyone dig in.