Serve warm, with the beans slightly softer than al dente. Jamie Oliver suggests serving with chervil , but as I'm yet to find this absolutely anywhere, I'm putting it in the 'Does Not Actually Exist' basket, along with Thai basil and blood oranges.
- Bring a pan of water to a fast boil, add the beans. Cover and cook for at least 4 to 5 minutes.
- Meanwhile, put the mustard and vinegar into a jam jar or bowl and, while stirring, add the olive oil to make a good hot French dressing. Season carefully with sea salt and freshly ground black pepper, then add the finely chopped shallot, the capers if you're using them, and the garlic.
- Remove one of the beans from the pan to check if it's cooked. If it holds its shape but is also soft to the bite, it's perfect. Drain in a colander.
- While the beans are steaming hot, dress them, tossing to distribute.
- Serve the beans in a bowl, sprinkled with chervil if you managed to actually find it.
Preparation time: 15 minutes
Cooking time: 5 minutes