Preheat the oven to 350°F. Line a baking tray with parchment paper. Arrange the bread slices on the tray. Bake until the bread begins to brown, 15 to 20 minutes, rotating the tray half way through, if necessary, for even browning. Flip the bread over and brown the other side, about 5 minutes. Make sure all of the bread is toasted through and fully dry. Remove the toasted bread from the oven and let cool.

Break or cut the toasted bread into ¾-inch cubes. Some of the bread will break when cutting into irregular shapes. Be sure to collect the crumbs when cutting. Divide the bread (including the crumbs) into four jars or containers. You should have about 1 ½ cups of bread cubes per jar, or 6 cups total.

Into each of the four jars, add: 1 teaspoon sage, 1 teaspoon thyme, 1/8 teaspoon onion powder, 1/8 teaspoon garlic powder, 1/8 teaspoon coarse sea salt and 1/8 teaspoon black pepper.

Tightly secure the lids on the jars or containers, store at room temperature, and prepare stuffing within five days.

To prepare stuffing, melt butter in a saucepan over medium heat. Use one tablespoon of butter per jar of bread cubes you are using. If desired, add chopped celery (one stalk per jar). Cook the celery until just softened, five to six minutes.

Pour in chicken broth or stock, 1/3 cup per jar you are using, and heat until simmering. Add the bread and herb mixture from the jar(s) and stir well. Add additional broth, if the mixture is too dry for your taste. Remove from the heat. Let the stuffing sit for five minutes before serving.