When we used to do a lot of business with the Indian community there were two restaurants that they used to recommend highly in the London area, one was in Wembley and the other was in Southall. Not the
Brilliant, which is popular with Michael Winner & the glitterati, but
Gifto's Lahore Karahi which is actually owned by Pakistanis.
Service can be a bit chaotic, with mains arriving before starters on occasions, but the food is both authentic and tasty and the food does arrive very quickly. It is a dry house so some people bring their own wine, but we usually buy beers from the nearby Indian corner shop!
Punjab-influenced dishes dominate, and the place is rightly proud of its tandoori specials - the tandoori lobster is really excellent. The mixed grill starters are impressive and the menu also has its share of elegantly flavoured dishes. Breads, dhal and sides are inexpensive and superb.
Well worth trying for an authentic experience if you're near the area...