Cut the block of tofu in half and then into 8 ½ inch thick slices. Place into a medium sized container and add in vegetable broth and garlic. Make sure the tofu is fully coated, then set aside to marinate for one hour.
Preheat oven to 400°F and line a large baking sheet with parchment paper or a silicone baking mat.
On a medium sized plate, mix together your Italian seasoning and arrowroot powder.
After about an hour, take your tofu slices, fully coat them on both sides with the arrowroot and seasoning mixture, then place onto the lined baking sheet. Place in the oven for 30 minutes, flipping halfway through.
Once finished, top with salt and pepper to taste and set aside.
Toast the sourdough bread and then coat one side of bread with the white bean pesto spread. Assemble the sandwich with two slices of the baked tofu, lettuce, tomato, and avocado. Close sandwich, cut in half, and enjoy!