I kept it all very basic. The slices of bread are just two squares of felt, sewn around the edges with a small amount of stuffing added in. The fillings are mainly just single pieces of felt, some with details sewn on.
I made two slices of ham, two slices of cheese, two pieces of cucumber, two slices of tomato and a piece of lettuce. They are all pretty much life size.
I didn't use a pattern, I just cut them freehand. There is a lot of inspiration for felt food all over the web, I particularly like the detailed tutorial for making a felt lunch bag at Skip To My Lou.
You might also like some of the other play food that I have made for the children's toy kitchen: