About 30-40 years ago I read a short story I liked but neglected to
remember either title or author. It has bothered me off and on ever
since.  In a nutshell I summarize it:  A Maigret/Poirot type French
police officer has spent a significant amount of time, in vain,
pursuing the suspected murder by a woman of three successive husbands,
nheriting substantial wealth from each.  After the officer retires he
locates the woman and, now unofficially, asks her how she managed the
trick.  The woman answers that she was the daughter of a celebrated
chef from whom she learned an extensive amount of culinary lore.  The
first of the three husbands was a nasty types and she did away with
him by deliberately
plying him with so much rich food and excessive copulation that he
died
prematurely.  The next two were similarly bad news, which she handled
using the same technique. Nothing illegal about that? The retired
commissaire (or whatever) thinks a little and makes his own bid by
observing that it sounds like a good way to die.  The lady sizes him
up and suggests "The treatment is not necessarily fatal."

I tried this one on the people at the "Mysterious Book Shop" on 56th
St Manhattan who I figured knew everything about their genre but on
this one drew a blank.  Can anyone come up with a couple of names -
author
and title?

I read a similar and possibly the same story.

I seem to recall that it was included in one of the Alfred Hitchcock
collections of short stories but I can't remember the author nor the
title.

could it be one of these listed: 
          http://www.multcolib.org/books/lists/foodfic.html           ?