In a mixing bowl, combine the shredded vegan cheese, chopped jalapeno, diced tomatoes, chopped green onions, freshly ground black pepper, and salsa. Mix with a fork or spoon until all the ingredients are combined. (note: the amounts indicated above are an approx. feel free to add more or less depending on your preference).
Spoon the mixture evenly on top of 1/2 the slices of bread and top with the remaining bread to close the sandwich.
Heat a non-stick pan on medium heat. Spread butter directly on the pan. Place one panini on the buttered pan and grill until that side is golden, pressing lightly.
Butter the pan again and flip the panini. Grill until the other side is golden as well and the cheese mixture inside is completely melted.
Slice the panini in half and serve hot with your favorite hot sauce.