Make the Blueberry Compote: In a small saucepan, combine the fresh blueberries, caster sugar, lemon juice, and water. Place it over a medium heat.

Simmer and Thicken: Bring the mixture to a gentle simmer. Cook for 5-7 minutes, stirring occasionally and gently pressing some of the blueberries with the back of a spoon. The sauce will thicken as the blueberries burst. Once it has a jam-like consistency, remove it from the heat and set aside.

Prepare the Bread: Lay your four slices of sourdough on a board. Spread the softened butter evenly across one side of each slice. This buttered side will be the outside of your sandwiches.

Assemble the Sandwiches: Flip two of the bread slices over (buttered-side down). On the unbuttered sides, layer half of the sliced Brie on each.

Add the Compote and Basil: Spoon the warm blueberry compote over the Brie, spreading it out but leaving a small border around the edges. Tear the fresh basil leaves and scatter them over the compote.

Complete the Assembly: Place the remaining slices of Brie on top of the blueberry layer, then top with the final two slices of bread, ensuring the buttered sides are facing outwards.

Grill the Sandwiches: Heat a large, non-stick frying pan or griddle over a low-medium heat. Carefully place the sandwiches in the pan. I find that pressing down gently with a spatula for the first minute helps create a fantastic crust.

Cook Until Golden: Cook for 4-6 minutes on the first side, until the bread is a deep golden brown and crisp. Carefully flip the sandwiches over and cook for another 4-5 minutes on the other side, until the cheese is completely melted and oozing.

Rest and Serve: Remove the sandwiches from the pan and let them rest for a minute before slicing. This helps the cheese set slightly so it doesn't all run out. Slice in half and serve immediately.