Vegetable Panade

Preheat oven to 350°F. Coat a 9-by-13-inch baking dish with cooking spray.

Heat oil in a large skillet over medium-high heat. Add onion and cook, stirring often, until tender and beginning to brown, about 5 minutes. Add raw vegetables, if using, rosemary (or thyme), salt and pepper and cook, stirring frequently, until the firmest vegetables are starting to become tender, 4 to 6 minutes. (If using roasted vegetables, cook them until just heated through.) Add garlic and cook, stirring, until fragrant, about 30 seconds.

Remove from heat and stir in broth, scraping up any browned bits. Transfer to a large bowl and add bread; toss to combine. Spread the mixture in the prepared baking dish and sprinkle with cheese. Coat foil with cooking spray and cover the baking dish with it, sprayed-side down.

Bake the casserole for 30 minutes. Uncover and bake until the top is golden brown and crispy, 15 to 20 minutes more. Let stand for 10 minutes before serving.