Hi. The filling for my Salted Chocolate Tart was quite thick before adding the cornflour mixture and the olive oil didn't blend in. What did I do wrong?
Nigella's Salted Chocolate Tart (from SIMPLY NIGELLA) has a ganache-type filling that is made by heating chocolate and cream gently together, along with cocoa, coffee powder, salt, vanilla and olive oil. From the description of this mixture, being very thick and the oil being visible, we suspect that the chocolate mixture was heated too much and caused the chocolate to seize. Chocolate melts at just above body temperature and can burn easily, so it is important that the heat is kept fairly low and the mixture is stirred gently, but constantly, and not heated for too long.
Unfortunately if chocolate seizes from the temperature being too high it is usually difficult to save, though you could try whisking in 1-2 tablespoons of cold water which may make it smooth again. We would also suggest removing the pan from the heat before all of the chocolate has melted and continue stirring gently. The remaining chocolate will melt in the residual heat of the pan and will reduce the risk of the mixture becoming too hot.