Building your own sieve can actually be a pretty simple process, all you need is some wire mesh - www.bwire.com - and something to fold the mesh over. As long as you are using some sturdy woven wire cloth - anything can be done! This way you can customize exactly what you are working with - if you want larger openings - you can buy mesh with larger openings, and if you need a really big straining area - then get a bigger piece of mesh - its simple. I always found the DIY aspect of the kitchen to be the best - and I really, especially do not buy things for my kitchen from overseas, their products are generally unreliable and almost disposable.
