Preheat oven to 350ºF. Coat a 4-quart shallow baking dish with cooking spray.

Arrange bread cubes on a large ungreased baking sheet in a single layer (use 2 baking sheets if there’s not enough room). Bake until lightly toasted, about 8 to 10 minutes. About midway through the cooking time, toss them with a spatula so they dry out evenly. Remove bread from oven and set aside; leave oven set to 350ºF.

Meanwhile, in a large skillet over medium-high heat, heat oil and butter together for 1 to 2 minutes. Add onion and celery; sauté until soft, about 3 minutes. Add thyme, sage, salt and pepper; stir to coat. Cook until herbs are fragrant, about 1 minute.

Transfer onion mixture to a large mixing bowl. Add bread, broth and chives; toss to combine. Spoon mixture into prepared baking dish and cover with foil; bake 20 minutes. Uncover and bake until top is golden brown, 15 minutes more.

Yields about 1 cup per serving.

Notes:
Leave the bread bag open and somewhat uncovered for 1 to 2 days (at room temperature) before making the recipe.

You can make this stuffing in advance and bake it just before serving. The stuffing will last up to 3 days in the fridge or 3 months in the freezer. Thaw overnight in the fridge before baking as directed.