Substitute for eggs in Macarons (No Legumes)
I believe you can use sun-flower lecithin (make sure you don't get soy-lecithin) as the foaming agent, optionally together with xanthan gum some or some other thickener to get the desired thickness you want.

You'll need to beat the lecithin+water+sugar until it gets foamy. And then fold in the almond flour.