Heat 1 tablespoon of the oil from the jar of sun-dried tomatoes in a pot over medium heat (use stock if making this without oil). Fry the onions until soft and transparent then add the garlic and fry for a minute or so more until soft and transparent.
Add the tomato paste and stir well. Fry for a couple of minutes, stirring frequently to prevent burning, until the tomato paste has darkened slightly in colour.
Add the sun-dried tomatoes, vegetable stock and can of crushed tomatoes. Bring to a boil then reduce to a gentle simmer and simmer for 10 minutes.
Remove from the heat and blend with an immersion blender or carefully transfer to a blender and blend, with the lid ajar to allow steam to escape, until smooth.
Blend in the coconut milk. Taste and add salt. If you find it a bit sour, add the sugar or follow one of the other tips mentioned in the blog post above. If you'd like it thinner, add another splash of stock.
You can enjoy the soup just as it is or you can add in some cooked pasta, basil, veggies or other suggestions mentioned in the blog post above.