Preheat the oven to 300°F. Spread the cubed bread evenly on a baking sheet. Bake for 40 to 60 minutes, stirring every 8 to 10 minutes until the bread is dry and crispy. Remove from oven and transfer to a large bowl to cool.

Increase oven temperature to 350°F. In a large stovetop skillet or pan, melt butter over medium heat. Add diced onions, sliced celery, and minced garlic. Cook for 4 minutes, stirring occasionally until softened and fragrant.

Pour the sautéed vegetable and butter mixture over the toasted bread cubes. Toss gently to coat. Add kosher salt, freshly cracked black pepper, minced sage, and parsley. Toss again to evenly distribute the seasonings.

In a small bowl, whisk the eggs until well beaten. Pour the eggs evenly over the bread mixture. Following that, pour 1½ cups of chicken broth evenly over the bread cubes. Gently stir or toss to distribute liquids without breaking down the bread. For a moister stuffing, add up to ½ cup more broth as preferred.

Transfer the bread mixture into a greased 9×13 inch casserole dish. Cover the dish tightly with aluminum foil. If not baking immediately, refrigerate for up to 24 hours.

Place the covered casserole on the middle rack of the preheated 350°F oven. Bake for 30 minutes covered. Then uncover and bake for an additional 10 to 15 minutes until the top is golden brown and crisp. Serve hot immediately.