Preheat the oven to slow 150°C/130°C (302F/266F) fan-forced. Grease two oven trays; line with baking paper.

Beat egg whites in a small bowl with an electric mixer until soft peaks form. Add sugar and food colouring, beat until sugar dissolves. Transfer mixture to a large bowl. Fold in essence, sifted icing sugar and almond meal in two batches.

Spoon mixture into a large piping bag fitted with a 1.5cm plain tube. Pipe 4cm rounds, 2cm apart, onto prepared trays. Tap trays on bench to allow macaroons to spread slightly. Flatten peaks lightly with a damp finger. Dust with extra sifted icing sugar. Stand for 15 minutes.

Bake macaroons in a slow oven for about 20 minutes or until dry to touch. Stand macaroons on trays for 5 minutes; transfer to a wire rack to cool.

For the white chocolate ganache, combine chocolate and cream in a small heatproof bowl over a pan of simmering water; stir until the chocolate is melted. Tint with a few drops of food colouring. Cover. Refrigerate until mixture is a spreadable consistency.

Sandwich macaroons together with white chocolate ganache.