Preheat the oven to 90C (195F) and line the baking tray with parchment paper.

Add the egg whites and sugar to a clean, dry bowl made of metal or glass (I use a stand mixer bowl). Mix with a rubber spatula and place the bowl over a pot with an inch (2-3cm) of slightly simmering water. Make sure that the water doesn’t touch the bottom of the bowl.

Heat the egg and sugar mixture while stirring continually, scraping the sides of the bowl occasionally until the sugar has completely dissolved. You can check by dipping one finger in the mixture and rubbing it against another finger. There should be no sugar granules left. Alternatively, you can use a thermometer and wait until the mixture reaches around 60C.

When done, place the bowl into the stand mixer fitted with a whisk attachment. Add the salt and start whisking on medium speed for a minute. Then, increase to high and whisk until soft peaks form. Add the vanilla extract and lemon juice and whisk to very stiff peaks. The whole process can take 15-20 minutes depending on your mixer.

When done, color the meringue using water-soluble food coloring (gel food coloring will work great). Or, paint stripes inside the piping bag fitted with the desired piping nozzle to achieve striped patterns on your meringue.

Fill the piping bag with the mixture and pipe the cookies onto the prepared baking tray. I make them around 1.5-inch (3-4cm).

Bake for 1.5 hours on the middle rack without opening the door of the oven. When time is up, turn off the oven, crack open the door, and let cool down completely like this. Serve!