Heat oven to 180C/160C fan/gas 4 and butter and line a 20 x 20cm baking tin. Tip the pistachios into a pan and toast over a medium heat for 3-4 mins until aromatic, tossing occasionally so they don’t burn. Set aside.

Melt the chopped white chocolate and butter together, either in a bowl set over a pan of simmering water or in the microwave in short bursts. Leave to cool slightly, then beat in the brown sugar with a wooden spoon. Add the eggs, mixing well after each addition, then stir in the rosewater and 1/4 tsp salt. Sieve in the flour and gently fold together.

Roughly chop the cooled pistachios, then add them to the blondie mix and fold in the white chocolate chips. Pour the mixture into the lined baking tin.

Bake for 35-40 mins until set and golden brown, then leave to cool completely before slicing. To serve, scatter with dried rose petals, if you like.