Assemble the sandwich as you like and toast the bread, if that is your preference. Brush a little grapeseed oil or avocado oil on the panini grill and pull the top down. Grill the tempeh for about 5 minutes or until you see grill marks. You will have to check it by lifting the top. If you do not have a panini grill, you can sauté the tempeh in a frying pan.
Tempeh Panini Sauce
Mash the avocado and olives together. Add the green onion, mustard, lemon juice and basil leaf. Mix, taste, adjust for seasonings, enjoy.