Preheat oven to 350F and oil and flour dust a 1.5 qt loaf pan.
Start with stuffing: Stack slices of bread, cut them in 1in cubes, spread out on a baking sheet and let dry in the oven for 10 minutes, making sure not to burn them, until they are dry and slightly golden.
While bread is toasting, sauté onion in vegan butter over medium heat until softened. Then add celery and mushroom and cook for another 5-7 minutes until soft.
Transfer to a bowl and add fresh herbs, salt and pepper, cranberry and chopped walnuts and stir to combine. Add in the dried bread and stir gently.
Add in the vegetable broth, stir until moistened, careful not to over mix.
Drain, rinse and pat the tofu dry. Wrap in paper towel and gently press to draw most of the water out of the tofu. Then place in a food processor with arrowroot, agar flakes, vegetable broth, sea salt, and pepper and mix into a smooth paste, adjusting seasoning to taste.
Use ¾ of the tofu paste to evenly line the bottom and sides of the loaf pan.
Gently fill the pan with stuffing mixture, then spoon on remaining tofu paste and spread evenly.
Cover loaf with a foil tent, making sure foil does not touch the tofu!
Bake for 50 minutes and cool for 10 before serving.