Heat the oil in a saucepan. Add the onion and pumpkin or squash and cook for about 4 minutes over a medium heat, until the vegetables have some colour.
Now add a splash of water, cover the pan and let the vegetables sweat over a very low heat for about 15 minutes.
Check that the mixture stays moist and add another splash of water, if you need to.
Add the garlic and cook for another couple of minutes, then the tomato purée, stock, beans and seasoning.
Simmer for 5 minutes then add the kale and cook for another 5 minutes. Check the seasoning and, if you like, serve with shavings of parmesan (or vegetarian alternative hard cheese).
If you have an old rind of parmesan simmer it with the stock for about 20 minutes before adding it to the soup - it gives the stock a great flavour.
You can use spinach instead of kale in this soup recipe, if you like.
For more delicious soup and stews see our collection of soup recipes.