Preheat oven to 350°F (175°C)
Grease a baking dish (9×13 inch or similar)
Spread bread cubes on a baking sheet and toast 10–15 minutes until dry and lightly golden
In a large skillet, melt 4–6 tbsp butter over medium heat
Add 1 chopped onion and 2–3 chopped celery stalks; cook 8–10 minutes until softened
Add 3–4 minced garlic cloves; cook 30–60 seconds
Add poultry seasoning, sage, thyme, salt, and pepper to taste
Optional: add 1–2 cups chopped mushrooms and cook until browned
Transfer toasted bread to a large bowl
Pour in broth gradually (about 1 1/2 to 2 1/2 cups), tossing until evenly moistened (not soggy)
Stir in the vegetable mixture
Optional: stir in 1/2–1 cup chopped fresh parsley
Optional: add 1–2 beaten eggs for extra binding
Spoon mixture into the prepared baking dish and dot with butter
Cover with foil and bake 25–30 minutes
Uncover and bake 10–20 minutes more until the top is crisp and the center is hot
Rest 5–10 minutes before serving