In a medium-sized mixing bowl, combine the flour, probiotic powder, thyme, salt, pepper and garlic. Pour in the warm water and whisk until smooth. Cover with a tea towel or clean cloth and set aside overnight or for 8-10 hours to ferment.
After allowing the batter to ferment and when you are ready to cook, heat the oil in a large frying pan over a low-medium heat. Add the leeks, thyme leaves and a pinch of salt and saute for 3 minutes allowing the flavours to release and leeks to soften.
Add the mushrooms and garlic and continue to stir until combined. Cook for 10 minutes or until softened, stirring occasionally.
Add the spinach and stir through until wilted.
Pour in the cream and coconut aminos and stir to combine. Simmer on a low heat for 5 minutes or until liquid has thickened.
Turn off the heat and stir in the nutritional yeast. Taste and adjust seasoning as needed, adding more salt, black pepper, coconut aminos or nutritional yeast to taste. Set aside whilst you cook the crepes.
Very lightly, coat a large frying pan with oil. Once hot, whisk the batter again and pour in 80ml of the mixture, quickly picking up the pan and rotating it to cover the base of the pan. Add more batter if needed to completely cover but make sure it’s a very thin coating. Increase the heat to medium-high and cook for 2-3 minutes until brown and golden. The crepe should easily lift but if it sticks, cook the crepe a little longer. Gently flip to cook the other side for 1-2 minutes until brown and golden. Transfer the cooked crepe to a lined baking tray or plate and place in the oven at a low temperature e.g. at 100 degrees as you don’t want to cook it further or lose malleability, just keep it warm until ready to serve.
Repeat step 7 with the remaining batter. After each crepe is cooked, place in the oven on top of the previously cooked crepe with parchment paper in between to prevent them from sticking together.
When ready to serve, you may need to warm up the mushrooms. Place a crepe on a plate, spoon the creamy mushrooms onto the centre of the crepe and either roll, fold in half or half again.
Garnish with fresh thyme leaves and serve immediately.