Remove the block of tofu from its package and pat dry with a clean towel. Using a sharp knife, cut the block into thin slabs and place the pieces in a shallow bowl or container.
To a small bowl, add the grated garlic, vinegar, tamari, lime, oil, parsley and coriander and whisk to combine. Pour overtop of the tofu slices then tilt the container side to side to make sure the slices are coated.
Heat a large skillet over medium high heat then add the oil. Add enough squash to cover the bottom of the pan without overcrowding. Allow to cook undisturbed for about 3 mins. Flip the squash and cook for 2 mins. Transfer to a plate and repeat with remaining squash.
Once all the squash is cooked, return all of it to the pan with the sliced garlic and sauté for 2 mins until the garlic is cooked through then sprinkle with a pinch of salt and transfer back to the plate.
Add a batch of tofu slices to the same skillet over medium-low heat. Cook undisturbed in the pan for 3 mins, then flip and cook for another 2-3 mins until golden. Repeat with any remaining tofu.
To a mortar and pestle, add garlic and salt and crush into a paste. Add basil, then move the pestle in a circular motion around the mortar to crush the basil into a paste. Add in the avocado, lime zest and juice then mash together until well combined.
To build the sandwich, toast your bread then spread the avocado mixture on both slices. Layer one slice with lettuce, then tofu slices, squash, some extra fresh basil, seal and enjoy.
