How to Make It
Preheat oven to 350°F.
Arrange bread cubes in a single layer on a baking sheet; bake at 350°F for 10 minutes or until toasted, stirring once after 5 minutes. Place bread cubes in a large bowl.
Heat 1 tablespoon butter and oil in a large nonstick skillet over medium-high. Add onion and celery; sauté 5 minutes. Stir in sage, thyme, rosemary, and garlic; cook 5 minutes. Add herb mixture to bread.
Melt remaining 2 tablespoons butter in skillet. Combine butter, stock, 1 tablespoon parsley, 1 tablespoon chives, pepper, and eggs in a bowl. Add to bread mixture; toss gently to combine. Spoon bread mixture into a 2-quart baking dish coated with cooking spray. Bake at 350°F for 40 minutes or until browned. Sprinkle with remaining 1 tablespoon parsley, remaining 1 tablespoon chives, and celery leaves, if using.