1/2cupraw cashews, soaked overnight (or a minimum of four hours, but longer is better here)
1onion, thinly sliced
For the tart:
One sheet of pre-rolled flaky pastry, thawed (check the label if vegan or vegetarian)
Baby spinach leaves
Marinated button mushrooms
Olive and pumpkin seed tapenade
For the cashew cream:
Start by caramelising the onions. Cook the onions over a low to medium heat with 1 tbsp of coconut oil, stirring occasionally. Once they're getting quite golden, add 1 tbsp maple syrup and continue cooking for another few minutes. You want deeply, darkly golden (but not burned) onions that are soft and sticky.
Reserve about a quarter of the onions for serving the tarts, and add the rest to your blender.
Add cashews, mustard, salt and pepper, and 1/4 cup of water to the blender and blend until smooth. You may need to add a little more water to help the mixture blend. Add as little as possible though, you want a thick cream.
Taste and add more salt, pepper or mustard to your liking.
For the tart:
Preheat oven to 190C fanbake.
Cut the pastry sheet in half to make two rectangles. Use a knife to lightly score a border about 1cm from the edge, the whole way around each piece.
Spread half of the cashew cream thickly on each rectangle of pastry, within the scored border.
Bake for 15-20 minutes or until golden brown and the pastry has risen and flaked beautifully.