How to Make It
In a large pot, heat the olive oil. Add the onion, garlic, anchovies, capers and crushed red pepper and cook over moderate heat until the onion is softened and the anchovies have dissolved, about 6 minutes.
Add the greens, season very lightly with salt and toss to wilt slightly. Stir in the water and vinegar, cover and cook over low heat, stirring occasionally, until the greens are tender, 10 to 15 minutes. Transfer to a bowl and serve.