Roasting the tomatoes is the whole recipe. It concentrates their sweetness, removes the raw acidic edge, and creates those jammy, slightly caramelised edges that give the soup its depth. The garlic goes in alongside them, getting sweet and mellow in the oven until it's nothing like raw garlic at all — you can squeeze the whole head straight into the pot. Blending half the soup gives you a silky base that holds the whole beans and remaining tomato pieces, which is the right texture. Serve it with serious bread.
Method
Roast the tomatoes
Preheat your oven to 200°C / 400°F. Halve the tomatoes and arrange cut-side up in a baking dish or roasting tin — they should be fairly snug so the juices don't evaporate too fast. Nestle the halved garlic head in among them. Pour over all the olive oil and season generously with salt and pepper.
Don't be shy with the olive oil. It becomes the backbone of the soup's flavour.
Roast for 35 minutes
Roast until the tomatoes have fully collapsed, are jammy, and the edges are starting to caramelise and catch slightly. The garlic should be completely soft — it'll feel tender when you press it. This is where all the flavour is built, so don't rush it.
Build the soup
Once the garlic is cool enough to handle, squeeze all the softened cloves out of their skins directly into a large saucepan. Add the roasted tomatoes and every drop of oil and juice from the pan — that's flavour. Add the drained white beans, stock, thyme, and chilli flakes. Bring to a simmer over medium heat.
Simmer and blend half
Simmer gently for 10 minutes to let everything come together. Ladle about half the soup into a blender and blitz until completely smooth. Pour back into the pot and stir through — this gives you a thick, silky base with whole beans and tomato pieces throughout, which is the right texture. Taste and adjust seasoning.
If using a blender, make sure the lid is held firmly and start on low — hot liquid expands.
Finish and serve
Ladle into bowls. Finish with a genuinely generous drizzle of your best olive oil — this is one of those dishes where it matters — and more chilli flakes. Serve with crusty bread for dipping into the broth.
Mike's notes
This soup is even better the next day once the beans have soaked up more of the broth. Make a double batch and refrigerate — it keeps for 4 days and freezes well.
In summer, use fresh vine tomatoes or a mix of varieties. In winter, good-quality tinned whole tomatoes roasted in the tin (drained first) work surprisingly well. The key is the roasting step — don't skip it thinking you can just simmer tinned tomatoes and get the same result.