(See Notes) Preheat your barbecue. Flatten the chicken thighs between 2 sheets of baking paper or cling film with a rolling pin, to a 1cm thickness. Discard the paper or cling film.
Lay the chicken thighs in a shallow dish and add the garlic, rosemary and olive oil. Season with salt and freshly ground black pepper and rub the herby garlicky oil into the chicken. Set aside to marinate.
For the herby mustard mayo, mix all the ingredients together in a bowl and season with salt and a little freshly ground black pepper. Set aside until you’re ready to assemble.
Your barbecue will be ready to cook the chicken once the embers have cooled down a bit or been preheating for about 20 minutes if it’s a gas one. First, cut the burger buns in half and toast on the barbecue until lightly charred. Remove and set aside.
Lay the chicken thighs on the barbecue and cook for 3 to 4 minutes on each side (depending on the heat of your barbecue – I use our Thermapen to ensure the chicken has reached 74C), until tender and cooked through. Add the bacon as you turn the chicken to be cooked on it’s other side. The rashers will take around 1 minute on each side to cook. Once cooked, remove the chicken and bacon from the barbecue and place on a clean tray to rest. Halve, peel, de-stone and slice the avocados.
To assemble the burgers, spread some herby mayo on the bottom of each burger bun and add a couple of chicken thighs. Layer the tomato, bacon, avocado and lettuce on top. Spread another spoonful of mayo on the top half of each bun. Sandwich together and serve with some chunky oven chips…absolutely delicious!!
Notes
You can make ahead by prepping to the end of step 3, up to 4 hours ahead.
In the magazine, and I assume Tom's book, the recipe uses chicken thighs and streaky bacon. We used thighs and back bacon as we didn't have streaky bacon in the fridge. In the video, Tom makes his chicken BLT with chicken breasts and streaky bacon. Any variation will be delicious!
The recipe is easily adapted if you’re cooking for less or more people. The first time we made it, it was to serve 3 as my youngest step son came for dinner.