Heat a large pan over medium heat and add 1 tbsp of olive oil. Heat for 20 seconds and add your crumbled tempeh. Cook for 5 minutes until the tempeh is slightly golden brown.
Add tamari, onions and garlic to the pan. Stir to combine. Cook for another 5 minutes until golden brown all over.
Form the tempeh mixture into a log shape and place the cheese on top. Add a splash of water to the pan and cover with a lid to steam and melt the cheese.
Prep the sandwich by adding 1 tbsp of mayo to the sub roll. Carefully scoop out the cheesy tempeh mixture into the sub roll and top with iceberg lettuce and tomatoes. Season the tomatoes with a pinch of salt and pepper. Slice in half and dig in! ????