Prepare the chicken: Lay the butterflied chicken breasts between two sheets of baking paper and gently pound them to an even 1cm thickness using a rolling pin. Season both sides generously with salt, black pepper, smoked paprika, and garlic powder. The aroma of the paprika hitting the raw chicken is the first promise of something good.

Cook the chicken: Heat 2 tablespoons of olive oil in a large frying pan over a medium-high flame until it shimmers. Lay the chicken in the pan; you should hear a satisfying sizzle. Cook for 4-5 minutes per side, until the underside is a deep, golden-brown colour and the chicken feels firm to the touch. Remove to a plate and let it rest for 5 minutes — the juices need to settle back into the meat.

Toast the bread: Wipe the pan clean and return it to a medium heat with the remaining olive oil. Add the bread slices in a single layer. Toast for 2-3 minutes per side until they are crisp and have taken on a patchy, biscuit-coloured hue. The sound of the bread scraping against the pan tells you it's ready.

Make the lemon mayo: In a small bowl, stir together the mayonnaise and lemon juice until smooth. Taste and adjust with a pinch of salt. This simple spread will cut through the richness of the avocado and cheese beautifully.

Slice the chicken: Once rested, slice the chicken breasts against the grain into 1cm strips. The interior should be white and juicy, with no trace of pink.

Assemble the first layer: Place three slices of toasted bread on your work surface. Spread each with a generous smear of lemon mayo. On the first slice, lay down a handful of lettuce, followed by a few rounds of tomato, a pinch of salt, and half the sliced chicken.

Build the second storey: Place a second slice of toasted bread (mayo-side down) on top of the chicken. Press gently. Now, add the avocado slices, fanning them out for even coverage. Follow with the cheese (if using) and another layer of lettuce.

Cap and secure: Top with the final slice of bread, mayo-side down. Press the whole tower gently but firmly with your palm. Insert four long skewers through the stack at the corners to hold everything in place. The skewers are not optional — they are the scaffolding that keeps your creation upright.

Slice and serve: Using a very sharp bread knife, cut the sandwich diagonally from corner to corner, creating two triangles. You will hear the crust shatter. Wipe the knife clean between cuts for a neat edge. Serve immediately, while the bread is still warm and the lettuce is at its crispiest.