Heat a medium pot over medium high heat and add a splash of water, the onion and garlic. Sautee until soft. Add the tomatoes and apple. You can choose to peel the fruit beforehand if you want a smoother soup, it’s up to you.
Cover the pot and reduce the heat to medium-low. Simmer until the tomatoes and apple are soft and falling apart. The time depends on how ripe they are - from 10 minutes for very ripe tomatoes to 20 minutes for not so ripe ripe.
Remove the pot from the heat and add the basil, 1 teaspoon of salt, vinegar and pepper. Blend until smooth with an immersion blender or carefully transfer the soup to a regular blender.
Make the cashew cream by blending the cashews, water and ⅛ teaspoon of salt in a small food processor. I like to make it a bit in advance and chill it in the fridge for a bit.
You can serve the soup straight away and hot or chill it in the fridge for several hours. Serve the soup with the cashew cream drizzled and swirled on top and a few basil leaves for garnish.