Place the tortillas on the baking tray for your toaster oven. If you have a pop up toaster, you can make these in an oven preheated to 350F instead.
On top of your tortillas, layer the beans, tomato slices, and greens. Place in the toaster and toast for around 7 minutes. Keep an eye on this, because the tortillas burn easily. If you're using an oven, bake for 5-10 minutes, or until the tortilla turns a nice, golden brown.
Plate up your tostadas and top with a little hot sauce, vegan mayo drizzle, and serve with a side of guacamole for dipping.