Sift your almond flour and powdered sugar using a very small-holed strainer into a large bowl - note: sifting is key! You need to get the finest form of flour you can, and the only way is sifting. Stir with a whisk and let it stand whlie you prepare another bowl with more ingredients.
Separate your 4 eggs , and use only the egg whites. Place them in a separate bowl.
Add in your 1/2 cup sugar and blend with a hand mixer, you should have stiff peaks with your mixture - then you know it's ready to add the dry ingredients.
Slowly add in your dry ingredients while mixing on low. Do NOT overmix!
Add in a tsp of green food colouring, gently fold it in. No overmixing!