Preheat the oven to 200°F (or the lowest temperature your oven allows)*.

Arrange the bread pieces on a couple of baking sheets.

Place the baking sheets into the oven and bake until the bread pieces feel somewhat dried out on their surfaces, 15-20 minutes.

While the bread is in the oven, place a medium skillet (oven-safe, if available) over medium heat.

Melt the butter in the skillet and let it heat up for a minute.

Add the celery and onion to the skillet and cook them, stirring occasionally, until soft, about 10 minutes.

Add the garlic to the skillet and cook for 1 minute more, until very fragrant.

Add the wine, rosemary, thyme, and sage to the skillet. Raise the heat and bring the wine to a simmer.

Allow the wine to cook until reduced by about half, about 4 minutes.

Stir in 1 cup of broth. Bring it to a simmer.

Lower the heat and allow the broth to simmer for 5 minutes, stirring occasionally.

While the broth simmers, stir the water and cornstarch together in a small bowl.

Add the cornstarch mixture to the broth and continue to let it simmer until it thickens up a bit, about 1 to 2 minutes.

Remove the skillet from the heat.

Remove the bread from the oven when it's finished drying out, and raise the heat to 350°F.

If you used an oven-safe skillet to cook the vegan butter mixture, you can add the bread directly to the skillet. Otherwise, place the bread into a medium (2 to 3 quart) baking dish, and add the onion and celery mixture.

Gently stir the bread and butter mixtures together until the bread is evenly coated. You can add up to an additional ½ cup of broth if necessary, but be careful to avoid oversaturating the bread.

Taste-test and season the stuffing with salt and pepper to taste.

Cover the skillet or dish and bake for 20 minutes.

Uncover and bake for about 20 minutes more, until dried out on top and slightly crisp around the edges.

Remove from the oven and serve.