Before we start, it is important for me to note that macarons are a little finicky, and many of the times in the instructions below might be different for you based on things like the humidity of your kitchen. A little trial and error may be necessary!

Weigh out your almond flour and powdered sugar, and place in a bowl together. Depending on how grainy or sticky your almond flour is, you can put the mixture in a food processor and pulse 10 times for 10 seconds.

Pass the mixture through a fine sieve. This part takes some time, and you may have to use your hand. If there are any very large grains, don't push them through, just set them aside for another recipe or put them through a food processor to make them smaller.

Set the almond flour and powdered sugar mixture aside.

In a stand mixer, beat your egg whites and sugar until stiff peaks form, 2 minutes on low, 2 minutes on medium and 2 minutes on high until they are very stiff.

Add your brown food colouring a little bit at a time until it is a light brown (2 gel drops for me, yours might be different depending on what brand you use), and then a little bit of yellow until it reaches the same hue as a hamburger bun and beat for another 30 seconds or until evenly distributed.

Gently fold your meringue and your almond flour mixture together with a large flexible rubber spatula. Be gentle, and move in circles, occasionally pressing the meringue against the sides of the bowl to deflate it a bit. Fold it no more than 50 times. It should become almost liquidy and sink back into itself when you're done. Some people compare it to lava.

Place parchment paper onto two flat cookie sheets. You can make it stick with just a little batter under each corner.

Pour the mixture in a pastry bag with a large, round nozzle (I used Wilton 10). Squeeze the macarons onto your baking sheets, holding your pastry bag at a 45° angle, and just release the pressure and pull away once you've got a nice circle 2 inches in diameter.

Set your macarons aside for at least 30 minutes, or until the top of the dome hardens a bit. Depending on how humid your kitchen is, it might take an hour or more, but that is how you get that really nice dome and the little 'feet'.

Preheat your oven to 320°F.

Bake the macarons for about 12-15 minutes in the middle rack of your oven. Keep a close eye on them. You'll know they're finished when they just come off the parchment paper leaving nothing behind.

In a bowl, mix all buttercream ingredients. It should be nice and smooth, thin enough to spread, but thick enough to be frosting. Split it into three, and add cocoa powder to one, red food colouring to another, and green to the last. Put them in three separate pastry bags.

When the macarons are cool, use a pastry bag with large circle tip (I used Wilton #10) to make the 'burger' with the chocolate buttercream. Add a green 'leaf' with a leaf tip (Wilton #366) with your green buttercream, and a smaller round tip (Wilton #6) to make the 'tomato' with your red buttercream.

Let the macarons rest for a day or two, otherwise they will be too crispy and not properly 'aged'.