I got some fab ones in M&S - I think they were Clarks originally. They were black leather and had a slight western heel, almond toe and a slight notch front. I ummed and ahhed as I thought they were bland, but very comfy and called them my 'sad' shoes i.e. not particularly fashionable. Oh my god I love them! They work under wide trousers and with most dresses with tights.
I do find summer work shoes with dresses a bit harder- I'd probably go for a chunky loafer.