Season and Cook the Chicken: In a medium bowl, toss the chicken strips with the olive oil, smoked paprika, garlic powder, onion powder, salt, and pepper until evenly coated. Heat a large frying pan over a medium-high heat. Add the chicken and cook for 5-7 minutes, turning occasionally, until it's cooked through and slightly browned. Remove from the pan and set aside.

Prepare the Avocado Mash: While the chicken is cooking, prepare the avocado. Halve the avocado, remove the stone, and scoop the flesh into a bowl. Add the lime juice, chopped coriander, and optional red chilli flakes. Mash gently with a fork – I like to leave it a bit chunky for texture. Season with a pinch of salt and pepper.

Assemble the Sandwiches: Lay out the four slices of bread. Spread the softened butter on one side of each slice. This buttered side will be the outside of your sandwich.

Layer the Fillings: On the un-buttered side of two slices of bread, layer your fillings. Start with half of the grated cheddar cheese, followed by the cooked chicken strips, and then a generous layer of the avocado mash. Top with the remaining cheese.

Close and Grill: Place the remaining two slices of bread on top, butter-side-up. Carefully place the assembled sandwiches into the same frying pan you used for the chicken (no need to wash it!).

Toast to Perfection: Cook over a medium heat for 3-4 minutes on each side. I find that pressing down gently with a spatula helps the cheese melt evenly and gives the bread a fantastic crust. The sandwich is ready when both sides are a deep golden brown and the cheese is completely melted and bubbling at the edges.

Rest and Serve: Remove the sandwiches from the pan and let them rest for a minute. This is a crucial step as it allows the filling to set slightly and prevents it from spilling out when you cut it. Slice in half and serve immediately.