1.Preheat oven to 150°C/300°F. Grease oven trays; line with baking paper.
2.Beat egg whites in small bowl with electric mixer until soft peaks form. Add caster sugar and few drops colouring, beat until sugar dissolves; transfer mixture to large bowl.
3.Meanwhile, push fresh strawberries (or thawed frozen berries) through a fine sieve; you need 1 tablespoon of strawberry puree.
4.Fold sifted icing sugar, ground almonds and puree into egg white mixture, in two batches.
5.Spoon mixture into piping bag fitted with 1cm (½ inch) plain tube. Pipe 4cm (1½ inch) rounds about 2.5cm (1 inch) apart onto trays. Tap trays on bench so macaroons spread slightly. Stand 30 minutes.
6.Bake macarons about 20 minutes. Cool on trays.
7.Sandwich macarons with jam. Dust with extra sifted icing sugar.
Do not be tempted to remove the macarons from the oven tray before they have cooled completely or they will stick.Note