If you have time, you could make this soup with dried white
beans instead of the canned ones; they'll need to be soaked
overnight and cooked for longer.
2 tbspextra-virgin olive oil, plus extra for drizzling 1Spanish onion, thinly sliced2garlic cloves, finely chopped, plus 1 extra clove, halved, for rubbing1 tspdried chilli flakes, or to taste1.2 kgcanned white beans, drained, rinsed1 litre (4 cups)vegetable or chicken stock2fresh bay leaves1½ tbspred wine vinegar, or to taste8 thick slicessourdough breadTo serve:coarsely chopped flat-leaf parsley and oregano
Heat olive oil in a large saucepan over medium-high heat, add onion and garlic, stir occasionally until tender (4-5 minutes), add chilli, stir to combine. Add beans, stock and bay leaves, simmer for 15 minutes, then pulse with a hand-held blender until partially puréed. Add vinegar, season to taste and keep warm.
Meanwhile, preheat a char-grill pan over high heat. Drizzle both sides of bread slices with a little olive oil, season to taste and char-grill, turning once, until toasted (1-2 minutes each side). Rub crostini with remaining garlic and place one slice in each serving bowl. Ladle over hot soup, scatter with herbs and serve with remaining crostini.