Soju is a popular Korean beverage roughly similar to sake but sweeter. You should be able to find it in Asian shops.
The flavour itself was rather good and the Soju and lemon went really with well with the onions. However, I found that it didn't yield as much sauce as I would have expected. Definitely worth a shot and very filling. - 17 Aug 2010 (Review from Allrecipes USA and Canada)
Really enjoyed this recipe! The onions were the highlight of the dish and as mentioned before the flavors go really well together. I upped the amount of Soju, onion, and lemon juice to make sure there was plenty to go around. My boyfriend is half Korean so there is always a bottle of Soju sitting around. Glad to finally have a great use for it! - 12 Jan 2012 (Review from Allrecipes USA and Canada)