Location: 2nd Floor by the Debut Hair Salon. Phone: 02-921-9982
Here's a map.
Ambiance: Can be a bit loud if it's full, but is usually quiet. They have big, bright white walls full of pictures and remnants of the middle eastern world, to include pictures, statues, tuk tuks, and such. The staff is mostly Korean, and occasionally shy, but very nice and welcoming once they work up the courage to talk to you.
Food: The food is good, some of the best Indian food that I have found nearby. I especially like the Lamb Korma at medium, it has a bit of spice tempered with a bit of sweet. I rarely venture past the medium spice level, as they don't joke with their spices. My partner regularly has the hot and has occasionally tempted the double hot, but doesn't suggest it, and he likes spicy. I have had many of their curries, Tikka Masala, Korma, Vindaloo, et al, and they are all quite tasty. I lean towards their lamb, because let's face it, I like lamb. The naan is good, garlic, honey, an even the specialty items found in the appetizer list. I do recommend that you skip the Samosas, while tasty, they tend to often times remain frozen in the center. Finally, if you like yogurt drinks, known as Lassi, they are available in many flavours. I, personally, go for blueberry. I say give it a shot. I have heard of better, but they are quite far from the Yongsan Base area, and I am usually lazy when it comes to dinner.
Won: 10 - 20,000 per person (including drink)
UPDATE: I no longer recommend Benares. At least as of 15 Dec, they have reduced the menu options and changed the quality of the food. The curry no longer has a spice intensity option, and instead is just bland, without flavor and even watery. Additionally, the garlic naan even managed to lack its previous oomph of flavor.