Warm up your panini press (or just a pan on the stove).
Slice the tomatoes.
Assemble sandwich beginning with a slice of bread (buttered on both sides), vegan cheese, tomato slices, basil, and a sprinkle of salt and pepper.
Place in panini press until golden lines form and cheese is melty, or pan fry until golden and crispy on both sides.
Option: Add avocado after after toasting the sandwich.