I cooked Nigella's Oeufs en Cocotte (from Nigella Express) as per the instructions in the recipe, but the yolks were solid. Should I have turned over down to 170C for Fan oven?
Oeufs en Cocotte, or eggs baked in small dishes, is a method of cooking eggs that should give a set whie and runny yolk (though you can cook the eggs for longer for firmer yolks). The eggs in their ramekins are cooked in a bain marie (a hot water bath) as this will temper the heat of the oven and gently cook the eggs.
There may be a couple of reasons why the eggs slightly over cooked. The first is that the eggs should be UK large (for the US this is extra large) as smaller sizes can cook more quickly. There is a note in the introduction to the book mentioning that eggs sgould be large. The fan oven could also cook the eggs slightly more quickly, though normally the bain marie will redcue the risk of this. Fan ovens should be adjusted for temperature as most recipes are written with temperatures for conventional ovens. Your oven handbook should give you a guide on how to adjust your own oven's temperature.Usually you do need to reduce the temperature by 20c/50F and may need slightly less time. Also make sure that the water in the bain marie comes at least halfway up the sides of the ramekins, as if it is too shallow it will not protect the cooking eggs properly.