Ham and mushroom gougere

[DutchOma]

I found a recipe for two for this and made the choux pastry without difficulty. Put it in a ring and expected it to come out as an oversize eclair. It didn't. It was flat as a pancake and crispy. Nice flavour, but the sauce had to go on top.
What went wrong?
Oven too hot/too cold? Not enough beating?
I used one large egg as instructed.

what recipe did u use?

Did you let the roux cool before adding the egg?

40g butter, 100ml water, 50 g flour. Worked a treat. yes, I did let it cool a bit before adding the egg, but not entirely.

It could be that the egg cooked too early, or the flour you used - bread flour is best, because of all the water, you need a high gluten flour.

Right, I will have another go sometime and use some strong white bread flour. I'll also do a lot more beating when the egg goes in.. I thought next time I'd just make heaps on a baking tray like you do for eclairs and fill them with the sauce.
Thanks for your help