Preheat oven to 250.
Scatter bread in a single layer on a rimmed baking sheet. Bake, stirring occasionally, until dried out, about an hour.
Let cool, transfer to a very large bowl.
Butter a 13x9x2 baking dish and set aside.
Melt 3/4 cup of butter in a large skillet over medium-high heat; add onions and celery. Stir often until just beginning brown, about 10 minutes. Add to bowl with bread; stir in herbs, salt, and pepper. Drizzle in 1 1/4 cups broth and toss gently. Let cool.
Preheat oven to 350. Whisk eggs in a small bowl, mix in 1 1/4 cups broth. Add contents to bread mixture; fold gently until thoroughly combined. Transfer mixture to the prepared dish, cover with foil, and bake for 40 minutes.
Continue to bake, uncovered, until stuffing has set and top layer is browned and crisp, about 30 minutes longer.