Slice the mushrooms and fry on oil until mushrooms are golden (about 4 min). Lightly salt and pepper and remove from heat to completely cool.
Combine the ham, spinach, artichokes, cheese, Parmesan cheese, mushrooms, mayo and tomatoes. Mix everything well. Lightly pepper.
Slice French bread into desired thickness. (I get around 24 slices.)
Add the mixture to each slice of bread and bake in preheated oven to 400°F for about 8-10 minutes. (Keep an eye on them, all ovens are different. Bake longer if you want the bread toasted more.) Enjoy.