In a bowl, whisk together the chickpea flour with sparkling water, baking powder, olive oil, rosemary, and salt, until you have a thickish batter. Let rest in the fridge for at least 15 minutes.
In a pan on medium heat, cook the chopped onion with some water and a pinch of salt for about 20 minutes, until the onion becomes brown and caramelised. At the 20 minute mark , add the balsamic vinegar and let evaporate.
Add the caramelised onions to the chickpea batter and incorporate well.
On a non-stick pan on medium heat, cook the chickpea batter pancake style for about 4 minutes each side. The frittata should be about 1cm | 0.4inch thick.
MAKE THE OLIVE TAPENADE
In a blender, blend the black olives, the garlic, the capers, the parsley, the orange zest, the olive oil and a tiny pinch of salt, until you have a smooth olive cream.
Serve the tapenade on top of grilled wild mushrooms for best umami explosion!