Haddock and spring onion twice-baked soufflés

I first ate a twice-baked cheese soufflé at Le Gavroche in the seventies. I couldn’t believe it. It was smooth as silk, light as air, wonderful flavour; everything a soufflé should be, but somehow richer. Which is not really surprising because the technique of twice-baked soufflés is to make standard little soufflés, allow them to cool, then put them in a deep dish and drench them in double cream. As the soufflé re-bakes it absorbs the cream, which replaces the original air pockets. So it r