Begin by preparing the bread. Cut the bread into small cubes. You can also tear it apart if you prefer it more rustic. Place the bread pieces on a large rimmed sheet pan and spread into an even layer. If you are making the stuffing the following day, you can allow the bread to sit uncovered at room temperature to dry out. If you are making the stuffing on the same day, preheat the oven to 300ºF. Toast the bread pieces in the oven until completely dried out, about 25 - 40 minutes. The exact amount of time will depend on the type of bread you’re using.

Prepare the flax egg. Combine 2 tablespoons flax meal with 5 tablespoons water. Whisk to combine and set aside for 10 minutes to thicken.

Lightly grease a 9x13 baking pan (or another similarly sized casserole dish) with oil or vegan butter.

Heat a deep saucepan over medium heat. Once hot, add the olive oil or vegan butter. Once melted, add the mushrooms. Cook until the mushrooms lightly browned and the moisture has evaporated. This will take about 10 minutes.

Add the onion, celery, garlic, chopped sage, and chopped thyme. Cook for 3-5 minutes, stirring occasionally to prevent burning, or until the vegetables are starting to turn golden. Add 1 teaspoon salt and pepper to taste.

Pour in one cup of the vegetable broth, and stir to deglaze the pan. Add the miso paste and stir to incorporate into the veggies. Transfer the mushroom mixture into a very large bowl (the biggest bowl you have so you have enough room for mixing). If you’re using a very large pan or Dutch oven, you can also just add the bread into the pan.

Add the flax eggs, dry bread cubes, and chopped parsley to the mushroom mixture. Toss well to combine. Pour 2 cups of vegetable broth over the mixture to moistened. Stir well, and let sit for a few minutes to allow the liquid to absorb. Toss again, and add more broth if needed. I like to taste a cube of bread here to see if it’s absorbed as much liquid as I like. If you want things softer, add more broth as needed.

Transfer the stuffing to your prepared dish. Spray a piece of aluminum foil lightly with cooking spray or brush lightly with oil to prevent sticking. Cover the pan tightly with the foil. If you’re making ahead, place the pan in the refrigerator now.

When you’re ready to bake, preheat the oven to 350ºF. Place the stuffing, still covered, in the preheated oven until warmed through, about 25 minutes. Then increase the oven temperature to 425°F and remove the foil. Continue baking until golden brown and crispy on top, about 20 minutes.