"Also, do you have a particular work by Amin in mind or just his recent body of work?"
Yes, I was thinking of his essays "pure economics" and "the ideology of political economy" in the book Spectres of Capitalism, which are well written (the whole volume is pretty interesting) but in the end do not, I think go beyond Keynes' scepticism towards the grand narrative of the equilibriating market system.
It is a case in point, I don't think that the Marxists ever wrote a good critique of neo-Classical economics, preferring to surrender the field to the Keynesians, and piggy-back theirs. I would be interested to know.