Method
- Heat the oil or butter in a large pot over medium heat. Add the diced onion. Cook for 3-4 minutes until softened. Don't stress about perfect chopping. Chunky onion is fine.
- Add the garlic. Cook for another minute until it smells amazing.
- Chuck in the tinned tomatoes. Drain and rinse the beans, then add them too. Stir everything together.
- Add the water (or stock) and the stock cube. Season with salt, pepper, and whatever dried herbs you've got. Stir it all up.
- Bring to a boil, then reduce the heat to low. Let it simmer for 15-20 minutes, stirring occasionally. The longer it simmers, the better it gets. If you've got 30 minutes, use them.
- Taste it. Adjust the seasoning. If it's too thick, add more water. If it's too thin, let it simmer a bit longer.
- Serve in bowls. Add chilli flakes if you want a kick. Grate parmesan over the top if you've got it. Serve with crusty bread. Optional upgrade: blitz half the soup with a stick blender for a creamier texture. But it's not necessary.