Boiled Silverside with Spicy Sauce

Besengek: it sounds Javanese, and it comes from Central Java. However, if you asked anybody there what it means, I am sure no-one could tell you. I have had this recipe for years, since I was a student in Yogya. The important thing is that the meat, after being boiled in one or two pieces, should be cut into quite large, but thin, steak-like slices. Silverside is what I make it with in London. There is also besengek ayam, more often called ayam bumbu besengek, which of course is made with c