Other than chilli pastes and chilli sauces, I rarely rely on bottled ingredients. But the Bull's-Eye barbecue sauce was recommended to me by a friend. The original sauce is seasoned with molasses, herbs and spices (there's also a Guinness-flavoured one), and, while not as good as some sauces I've tasted by real barbecue pitmasters, it's fine for barbecued-meat sandwiches if mixed with some vinegar and chilli oil. The sauce sells for HK$27.60 for a 510 gram bottle at Great (Pacific Place, Central, tel: 2918 9986).
I love the nutty taste of buckwheat flour. But it's a delicate grain and the standard 2.5kg bag goes bad faster than I can use it. So I was pleased to find Bob's Red Mill organic buckwheat flour in 680 gram bags at a reasonable price (HK$27.90) at Great. Buckwheat flour is essential for blini and galettes (savoury crepes), and you can add it to bread.
Furikake, or rice 'sprinkles', are sold widely in Japan. In Hong Kong, the best selection I've found is at Fresh Mart in the basement of Sogo in Causeway Bay (tel: 2833 8338). Shelf after shelf of furikake hold bonito flakes, seaweed, sesame seeds seasoned with yuzu, wasabi or shiso leaf (my favourite), as well as a Hello Kitty version. Prices range from HK$18 to HK$48.