1) Butter one side of each slice of bread (for frying up like a toasted cheese sandwich). Put mustard on other side and top with tomato and onion. Fry up on medium heat until each side is golden brown dash a teeny amount of salt on toasted sandwich.
The mustard will give sandwich a creamy texture and taste, yum!
Serve with tomato soup and vegan chips!
Source of recipe: there's an Italian restaurant in town who does something similar, but not vegan...I thought it looked tasty on the menu, so I came home and made up my own vegan version! delish! SUPER EASY!