Preheat the oven to 250°F. Cut the bread loaf into 1" cubes and add to a large baking sheet. Spread out into an even layer. Toast for ~45 minutes until crispy and golden brown. Add to a large mixing bowl and set aside.

Increase oven temperature to 375F. Grease an 8x8" baking dish with vegan butter. An 9x12" baking dish also works.

Add 1 tbsp olive oil to a large heavy-bottomed pot (like a dutch oven) over medium-high heat. Add sausage and crumble using the back of a wooden spoon. Cook for 3-4 minutes until browned. Drain all the grease, pat dry, and add to a small bowl and set aside.

Add butter to the same pot over medium-high heat. Once melted, add the onion, fennel, celery, and pinch of salt. Cook for 6-7 minutes until soft and light golden brown. Stir in the garlic and cook for 1 minute. Add the fresh herbs, salt, and pepper. Cook for 2 more minutes until fragrant. Remove from the heat.

Add cornstarch to the bread. Toss well to fully coat the bread in the starch. Add the aromatic herb mixture and sausage. Use a wooden spoon or spatula to carefully fold the ingredients together.

Drizzle over ⅓ of the broth, fold in carefully, and repeat until all the broth is gone. Press the stuffing down into the prepared baking dish. Cover with foil and bake at 375°F for 30 minutes. Remove foil and cook for 10-15 minutes until golden brown. Let stuffing cool for 15 minutes before serving.