I can certainly vouch for Raffaella from 81 Hills and a Mill!
She specialises in high standard patisserie products (so in case you are looking for a great looking, delicious home-made cake, Raffaella is great!). She also does savoury canapés, mainly pizzette (small pizza's of which the puffy pastry is home made from scratch), small Panini (small sandwiches using home made bread), sausage rolls with an Italian twist, home made grissini with parma ham, sun dried tomato focaccia etc. Typical Italian style rustic canapés.
The website doesn't show all her options, so the best thing to do is to phone/email her to discuss your options.