You will need 3-4 baking trays to be double lined with baking paper, depending on the size of your macarons. Have these prepared before hand. You will also need to prepare a piping bag with 1cm hole in nozzle. In your electric mixer place first 2 egg whites and start whisking until frothy, about 2 minutes. While egg whites are mixing, put 150g caster sugar & 50g water in small saucepan and turn on medium heat. Start adding 40g of sugar to egg whites and let them whisk on a medium speed while sugar syrup is coming to a boil. This should only take a few minutes, you want your egg whites to be white and thick and fluffy. Once syrup is boiling, this is the time to add coloring and essence. I like to make my macarons very bright so don't be shy with the coloring. remove colored syrup from the heat and while the egg whites are still beating, slowly pour a drizzle from the syrup into the mixture until all gone. You want this to be gradual and slow but should only take about a minute. Now you leave to whisk on a medium speed until the bowl is cool again, this will take about 5-6 minutes. While your egg whites are whisking you need so comdine the almond meal & icing sugar by sifting through a sieve & into a large mixing bowl. This will break up lumps and give you a nice smooth consistancy for the perfect macaron. Mix the extra 2 egg whites into the almond meal mixture to form a smooth paste. You should now have a wonderful looking egg mixture that resembles a thick merang and is at room temperature. Spoon egg whites into almond meal mix and stir it in with a spatula. You don't have to be overly careful with "losing air" the mixture is quite robust at this stage and can handle a bit of rough treatment. Just make sure it is thoroughly combined. Spoon batter into piping bag and carefully pipe rounds that are about 1" across with 2cm between as they will spread a little. This is the best size for me, I like them petit and this is how the French make them. Store bought Macarons are often too big and awkward to eat. Once you have piped them all they need to be left to "dry out" for a couple of hours. You know when they are ready to go in when you can gently tough the top of one and it has formed a skin, if the mixture goes onto your skin it is not ready yet. Heat your oven to 270 with a rack in the center and nothing else in the oven. Place just one tray at a time in the oven and try not to open the oven while they are cooking. It doesn't take long, my oven is exactly 12 minutes, you may have to experiment to get your perfect time as all ovens vary. Once they are ready to come out, remove the entire sheet from the tray but leave the Macarons on the paper to cool on a wire rack. Once they are completely cooled they should easily peel away from the paper. This is a recipe that I have "tweaked" to suit my kitchen, you may have to adjust to suit you but don't give up if the first batch don't work, they can be hit and miss even for the experts! So worth the effort. The best way to serve these delightful treats is to sandwhich together with a nice thick frosting, matching similar sized shells for best presentation, cool and serve. They will keep in your freezer in an air tight container very well too so they can be made in advance.