Yes there is nice food in Brunei.
Soriso in Regent Square Kiulap is my favorite (Italian), but I like also this small chinese vegetarian in Kiulap (facing Hua Hu), or Kai Zen for sushi's, or just the night market in Bandar, the one near the blue church with wonderful local food for very cheap. You can choose your fresh see-food and they will cook it the way you like! Kebabs are great there as well. Nur Wanita in Kiarong has great Thai food.
For UK style, try Fleur de Lys or the Riverview hotel's restaurant. For Fish and chips, maybe the Serasa Yatch-Club. But as a French I have trouble to link decent food with UK food.... sorry. (it's a joke off course, but it is true that I can't tell you if a fish and chips is good or not)