Step 1: Place the stock, peppercorns and bay leaves into a wide high side pan, bring to the boil then reduce to a simmer. Then place the chicken breast into the stock.

Step 2: Simmer until the chicken breast has internal temperature of 63C (it should take approximately 10 minutes for the chicken to reach 63C).

Step 3: Remove the chicken breasts from the stock and place onto a tray lightly covered with foil to rest until cooled.

Step 4: Remove the skin from the chicken and dice.

Verjuice Mayonnaise

Step 5: Place the egg yolks, Verjuice, lemon zest, mustard, tarragon and salt in a food processor or blender and blitz on high for 2 minutes.

Step 6: With the motor running, gradually pour in the olive oil, then the grapeseed oil in a slow steady stream until incorporated and thickened.

Step 7: Store in an airtight container and refrigerate until required.

Compiling the Sandwich

Step 8: Place the chicken in a mixing bowl and add 160g of the Verjuice mayonnaise and mix together well with ½ teaspoon of sea salt & freshly ground black pepper to taste.

Step 9: Divide the chicken mix into 3, placing each third into a slice of the bread, top this with the sliced avocado and rocket leaves.

Step 10: Cut in half.