Everybody knows Asian people don't eat dairy, right?
Wrong. The Vietnamese eat dairy. Besides the ubiquitous sữa (sweetened condensed milk, which shows up in cà phê sữa đá, the unbelievably amazing Vietnamese iced coffee with milk), Vietnamese people took a page from the French and started eating yoghurt.
Even the name for this sweet cousin to Danone comes from French: while da ua doesn't look like a cognate of anything in French, its Southern Vietnamese pronunciation, “yah wah”, is pretty close to the French word yaourt.
Da ua isn't made in the way you'd expect, however. Fresh milk is not very easy to come by in Vietnam, and it's not cheap when you do find it; da ua, then, is made from condensed milk, a little bit of whole milk, some water and a bit of old da ua to start it. The flavor is tart and sweet at once, like the fresh version of that tart yoghurt that made its way through OC's froyo scene a year or two ago; while it has a haunting hint of vanilla, there's no flavoring in it.
The best da ua recipe I've ever seem came from Todd Porter and Diane Cu, Orange County's own White on Rice Couple. It's so easy a child could do it (though boiling water and children are not a good combination).
That said, I am lazy and I don't keep small jars around on the off chance I'm going to make some da ua, so I tend to buy mine from Vietnamese groceries. The best I've found so far is from OC Poultry and Rotisserie (2117 E. Ball Rd., Anaheim; 714-780-0225), but absolutely any bánh mì shop, Vietnamese grocery store or deli will have it, stored in plastic cups about six inches tall with flimsy plastic lids.
Once you've got your hands on it, eat it with fruit. It's excellent with tropical fruits such as mangoes and papayas, but I love it on melon. It'd be amazing with pomegranate seeds and some muesli or granola sprinkled on top as breakfast. It is sweet, however, so don't make anything like tzatziki or raita with it.