Heat 3 tbsp olive oil in a large pan; once shimmering add the garlic and chilli flakes and fry until the garlic is very lightly golden, about a minute. Add the anchovy fillets and fry for another minute, stirring so that the anchovies melt into the oil. Add the watercress and cook briefly until just wilted then remove from the heat. Using a stick blender or food processor, blitz with the herbs, the zest of half the lemon, another 4 tbsp olive oil, a pinch of salt and lots of black pepper. Check for seasoning.
Drain the butterbeans into a sieve set over a bowl to catch all of the bean liquid. Stir the butterbeans into the greens and add the bean liquid little by little until you reach the consistency you like (I like it pretty loose). Spoon into bowls and crumble over the walnuts. Top with the remaining lemon zest, extra chilli flakes and a good drizzle of olive oil. Cut the lemon into wedges to squeeze over (please don't skip this bit, it makes a big difference).
HUGE thanks to the legend that is Florence Blair who let us share this #beanspo on our website for all you champs to enjoy. Florence creates loads of amazing recipes, check them out on their instagram here.
