Years ago, about 1981 I think, I watched a film on TV. It might have had Hywell Bennett in it and Hayley Mills. But it might not. One of them is a crazed psycho killer (plot twist - it's not the one we're led to believe). There is talk about how long to takes to boil an ostrich egg (30 minutes. Fancy having to wait that long for breakfast is mentioned).
I can find three films on IMDB in which they co-starred but I don't think it's any of them. (Twisted Nerve, Family Way, Endless Night)
Come on. Scratch my itch.