Soften the four-corner beans: Steam the sliced four-corner beans for 2–3 minutes until they turn bright green but remain crisp.
Cool immediately: Rinse the steamed beans under cold water to stop the cooking process, then drain them thoroughly.
Combine the vegetables: In a large salad bowl, mix the cooled four-corner beans, long beans, tomatoes, cucumber, and spring onions.
Season: Sprinkle the ground black pepper and a pinch of sea salt over the vegetables. Toss well to distribute the seasoning.
Add the avocado: Add the avocado cubes last. Gently fold them into the salad, taking care not to mash the pieces, and serve immediately.
