Leon,
I've had climbing onions for over 40 years; they are really neat plants. The only "leaf-like" leaves you'll see are the ones coming from the young bulb. As the plant matures, the basal leaves become tunicated and succulent to form the bulb (just like the BASES of the leaves are in typical onions). What you have growing is the stem which will form the vining showy part of the plant, therefore, "climbing" onion. This stem will do best if you provide it something to climb on, otherwise it will sprawl until it finds something to climb. As the stem matures, 1/4 - 3/8" greenish flowers will form at the ends of some of the stems. The mature leaves on the climbing stem are tiny and scale-like(the stem and bulb leaves do virtually all of the photosynthesis); you'll find them at the nodes of the stems (look just below where a stem branches off from another).
Good luck, Genepaul
PS: They like a rather dry, dormant period after flowering, so when the stems start to yellow, flowers or no flowers, stop watering for a few months. Also the bulbs should have only their lower portion below soil level - provide well drained soil, and do not bury the bulbs.