"Mark Darras looks an interesting fellow. I know nothing about...

"Mark Darras looks an interesting fellow. I know nothing about Islamic finance ... but it seems I might be about to learn [although I do happen to know an Arabic business saying "If you can't .... your brother, who can you ....? So I hope it's better than that]."

I can't say I know much about Islamic finance either.

From good ol' wikipedia - https://en.wikipedia.org/wiki/Sharia_investments

"It is an attempt to instill communal, ethical and socially responsible values into investing.^[3] E.g. It prohibits taking undue profits, overcharging of commodities in scarce supply, manipulation of demand-supply gap to the benefit of hoarders, etc., It also does not allow excessive debts, It prohibits investing into Tobacco, Cigarette, Alcohol, and other domains which are harmful for health. Hence it brings in a sense of responsibility as well as humanity into how your investment will give you fair returns by preserving the ethics and values."