Heat oven to 140C/120C fan/gas 1 and line 2 large baking sheets with baking parchment. First, set up your piping bags. You will need 3 disposable piping bags for the 3 flavours. Using a wet paintbrush, paint lines of undiluted food colouring along the inside of the piping bags. Be quite generous, because you want bold colours. Wash the brush well between each colour so they don’t mix. Snip off the end of 1 bag and drop in an extra-large round piping nozzle, then put the bags to one side.
Tip the egg whites into a large mixing bowl or table-top mixer – make sure it’s grease-free before you start. Whisk the eggs with an electric hand whisk or in your mixer, until they hold soft peaks. Begin adding the sugar 1 tbsp at a time, whisking continuously, until you have a thick and glossy meringue, which will hold up in a stiff peak on the end of the whisk. Divide the meringue into 3 bowls and swirl through your chosen flavourings (to correspond to the piping bag colours). You want to achieve a marbled effect rather than thoroughly mixing it all in.
Put the piping bag fitted with your nozzle into a tall glass or jug and roll the piping bag down over the lip of the jug to hold it in place. Fill the bag with the correct flavoured meringue to match the colour in the bag. Lift up and twist the end to seal.
Hold the piping bag about 2cm vertically above the baking tray. Apply an even pressure to the bag, slowly lifting the bag as you squeeze, to make a smooth round meringue, approximately 6cm wide. To finish with a nice peak at the top, push down a little on the mixture then quickly pull the nozzle away.
Continue until all the mixture in the bag is used up, leaving enough room for the meringues to spread a little. Quickly remove the nozzle, wash it and dry well, then drop in the next piping bag. Continue with the remaining mixtures until it they are all used up and you have 2 trays covered with 3 colours of meringues.
Bake for 1 hr, turning the heat down to 120C/100C fan/gas ½ for the final 30 mins. Remove from the oven and cool on wire racks while you make another batch of meringues with the remaining 3 flavours, if you like. Can be made up to a week ahead and kept in an airtight container, or serve with our flavoured creams (see tips, below).
