Ultimate chicken sandwich

Preheat the oven to 200°C/400°F/gas 6.

Season the chicken thighs with sea salt, then lay in an oven-proof frying pan with 1 tablespoon of the oil, skin-side down. Place the pan on a medium heat, allowing the fat to render from the skin as it heats up, and fry for 8 to 10 minutes, or until crisp and golden.

Flip the thighs, finely grate over a layer of cheese, then transfer the pan to the oven and bake for 20 minutes, or until the chicken is cooked through and the cheese is deep golden brown and lacy. Set aside to cool completely.

Crack the egg into a tall jar, add the mustard, then peel and finely grate in the garlic along with the lemon zest. Squeeze in half the lemon juice, add a pinch of salt, the anchovies (oil and all) and the remaining vegetable oil, and leave to settle for a few minutes.

Slowly push a hand blender to the bottom of the jar, then blitz without moving it around. Once things start to look pale and emulsified at the bottom, slowly bring the hand blender up through the mix to combine the remaining ingredients. Seal the jar and place in the fridge – it will keep for up to 3 days.

Shred the lettuce on a board and toss with the remaining lemon juice. Pick the chicken meat and skin from the bones on the board, then toss with the crispy cheese.

Slice the focaccia squares through the middle, spread a thick layer of the Caesar mayo over the bottom half, pile on the cheesy chicken and lemony lettuce. Pop the remaining bread on top, slice each sandwich in half, then wrap in greaseproof paper and get going!