I've been eating at the Halal for over 20 years (my dad over 40 years). The deco may be dated but the staff are very friendly and the food is awesome.
The food really sets the Halal apart from its competitors. Every dish has a very distinct, authentic flavour and these flavours are never drowned out regardless of the 'heat' of the dish. I would recommend the plain mutton curry as a great place to start. What could be a bland, bog standard dish is one of the highlights in terms of flavour. The Karahi chicken and Tikka dishes are also very very good but to be honest there are so many excellent dishes on the menu.
On top of the excellent food the value is incredible. A firm favourite that has maintained it's standards for many decades. Thoroughly recommended.