Runner beans are a lovely vegetable, much more versatile than you might think. They have far too short a season, so use them while stocks last! I sometimes like to add a little finely chopped hard-boiled egg to the gremolata in this recipe, which works rather well.
Cook the beans in plenty of boiling salted water for 4-5 minutes, then drain. Heat the butter in a shallow pan, add the beans and toss together. Season with salt and pepper, then place in a serving dish and keep warm while you prepare the gremolata.
Heat a heavy-based frying pan until slightly smoking, add the bacon strips and fry until they are golden and have released their fat. Add the breadcrumbs and butter and sauté until lightly golden and crisp. Mix in the parsley and lemon zest, then add the walnuts and season with salt and pepper. Spoon the gremolata over the beans and serve immediately.