Soak the cashews in boiling water for at least 15 minutes. Drain, then blend with half a cup of fresh water until thick, smooth, and creamy. If you don't have a high-powered blender and it struggles with the thickness, add a little of the stock from the recipe to thin it and make it easier. Set aside.
Set a wide saute pan/skillet over medium heat. Add the vegan butter. When hot add the onion. Cook for 5 minutes until just starting to color lightly, then add the garlic. Cook for 2 minutes more stirring frequently.
Spoon in the tomato paste, chili flakes, and Italian seasoning. Cook for another couple of minutes stirring frequently until the tomato paste darkens slightly.
Add the sundried tomatoes, drained chickpeas, stock, nutritional yeast/parmesan, salt, pepper, and the cashew cream. Use a spatula to scrape the blender out well so you don't waste any. Stir and allow to simmer gently for a few minutes until almost thickened to your liking.
Throw in the optional greens. Cook for a further 2 to 3 minutes until tender then serve immediately. If at any stage the sauce gets a little too thick add a few drops of water to thin.
