Thinly slice the garlic cloves and chop the salad onions.
Cut the boiled potatoes into bite-sized chunks.
Using a bean slicer, shred the runner beans into long strings, then cut them in half.
Heat the oil in a frying pan and soften the garlic and salad onions for a minute.
Add the beans and lemon juice. Let it sizzle for a few seconds, then add the potatoes, Boullion and a small glass of water.
Bring to a boil, cover and sauté for about 5 minutes, until the beans are tender and the potatoes have warmed through.
Season to taste with salt and pepper, and sprinkle with lemon zest and a few fresh mint or parsley leaves.