Finally, I have found decent Thai in London. It's not the cheapest, but it is of acceptable quality, i.e. comparable with what I would pay to eat in Australia. Now, £6.50 (AU$15.45) is very expensive for green curry but it is acceptable for eating out prices in London. The beautiful surroundings also make it a nice dining experience. Several large tables have big square trays of water with flowers floating on the surface. I dare say the constant renewal of water and flowers contributes to the cost of the establishment.
Zimzun is at the Fulham Broadway shopping centre (cheesy slogan alert: Life Begins at FBDY) on the same level as the cinemas. I ate a lovely roast duck salad (yum ped) for £7.50 whilst my friend P had duck and spinach fried rice for £6.25. The duck was succulent and correctly dressed with a well-balanced fish sauce and lime vinaigrette. P's fried rice was tasty and aromatic with chewy individual grains of rice kissed with garlic oil. (This last turn-of-phrase is a nod to the "sun-blushed" tomatoes I saw in the deli up the road from me.)
Notice in the website that they do not advertise themselves as being a thai restaurant, but an Oriental one. This is an interesting distinction, as the entire menu is thai. There is not a note of Chinese, or even more closely related Vietnamese or Malaysian dishes. This must be a marketing strategy - perhaps they don't want to associate themselves with pub food or tacky restaurants, which are the places where Thai food is mostly served in London.
We also ordered dessert - I had lychees on ice whilst P had mango ice-cream, which turned out to be Tesco's mango sorbet. A little disappointing, but when he complained to the manager she apologised and took the charge off the menu.