3. Put the still frozen green beans in the wok with a tablespoon of water, season with salt and pepper, and cook over medium heat and covered for about 8 minutes. Check that the beans are slightly crunchy, then add the lamb, the remaining sage, and the drained flageolet beans. Reheat over medium heat for 3 minutes, gently stirring to avoid damaging the beans. Adjust the seasoning and serve immediately.