Line two large baking sheets with baking parchment.
Sieve the almond flour and powdered sugar into a large bowl.
Place the eggs whites into a stand mixer and start to whisk on medium until they become foamy and opaque between 1-2 minutes.
Add the cream of tartar and whisk for a further 5-6 minutes before slowly adding the sugar one tablespoon at a time beating for at least 30 seconds between each spoonful allowing it to dissolve.
Continue whisking until you have soft peaks, a further 6-7 minutes.
Add in the food colouring until you have your desired colour.
Continue whisking until you have stiff and glossy peaks.
Gently fold in the almond sugar mixture to the egg mixture – approximately 50 folds until you have a batter that is thick but which runs off the spatula continuously.
If it is not quite ready, fold another five times then check again and continue with this process until you have the perfect batter.
Be careful not to overmix or it will become too runny!!
Pour into a piping bag with 3/8 inch round tip and holding the bag at a 90 degree angle , steadily squeeze the batter onto the baking sheet until you have a one inch circle.
Stop squeezing and twist the bag to detach the batter.
Repeat piping leaving one inch between each circle until the sheets are full.
Tap the sheets on the counter top to remove any air bubbles – pop any remaining bubbles with a toothpick.
Set aside uncovered for between 35-45 minutes until a skin has formed on the top of the macarons – they should be dry to touch when ready.
Place in the oven preheated to 325 f and bake for 10-12 minutes until they have puffed up.
Place the whole parchment sheet onto the cooling rack immediately to allow to cool, do not leave to cool on the baking tray.
Once cooled completely, fill with the cooled chocolate ganache.
These will keep in an airtight container for two days.