It looks to me from a quick Google for "Grabbi" and "Spice" in juxtaposition as if some may use it to describe "curry gravy" (i.e., curry sauce); "b" and "v" are not distinguished in some languages (e.g., Catalan), so it is possible to conjecture that that is how the usage arose. Here is a quote in context :
"How to make Butter Chicken the way a high street curry restaurant cooks it. You'll need some grabbi/gravy as a base for the sauce (excellent recipes available on the RCR real curry recipes site). For the chicken tikka, follow the instructions on a jar of Tikka paste such as Patak's. The rest are kitchen store cupboard ingredients. The smoking coal part is something that Indian families do at home and I'm not aware of any restaurant that does it; I do it because the kids enjoy it."