(NYTIMES) - The fight against food waste is not a new one. Stale bread, for instance, has long been precious in bread-eating cultures, where to waste even a slice is a kind of sin.

A hard baguette, a loaf that is too dry to cut, even the leftover heels and crusts - all have potential in the kitchen.

There are lots of traditional recipes meant to use up old bread, which excels at absorbing flavours.

There is panzanella, the Italian bread salad; or fattoush, a Lebanese one made with pita. Spanish migas marries shards of old bread and olive oil. French onion soup, with its cheesy, soup-soaked toast, is among the more well-known strategies.

A less-famous dish, but no less praiseworthy, is the panade. Imagine a sturdier onion soup or a soupier lasagna, made with bread instead of pasta, layered with cheese and vegetables, moistened with broth, and baked. Inside, it is delightfully soggy, while the top is golden, crisp and cheesy.

A panade satisfies the way a really good grilled cheese sandwich does or well-baked macaroni and cheese. This panade is essentially a savoury bread pudding interspersed with layers of caramelised onions, winter squash and grated alpine cheese, such as Gruyere or Comte.

The onions are the most important part. It is essential that they be slowly browned and well seasoned, so they add their flavour to the cooking liquid.

You could also use another vegetable instead of squash, such as stewed tomatoes or cooked leafy greens or sauteed mushrooms.

To build this humble dish, you need slices from a sturdy hearth-baked loaf. A large, European-style sourdough whole-wheat bread, made with a wild yeast (levain) starter, is ideal. You can make a panade from day-old slices, but older slices that are completely dried out work fine too.

If you do not have stale bread on hand, you can easily "make" it. Keep your sliced bread in a cloth or paper bag and let it dry slowly. As long as it can breathe, it will not grow mold. It will be there when you need some homemade breadcrumbs or croutons.

Water is a fine choice, with so many onions and herbs in the dish, but a quickly made vegetable broth will add another dimension of flavour. Simmer six cups water with two cups (combined) chopped leeks, onions and celery. Toss in a bay leaf or a thyme sprig and some squash peelings and cook for 30 minutes. Good chicken or beef broth are also options.

You might consider a panade as a substitute for bread stuffing and serve it alongside a roasted holiday bird. On other cool days, it shines as a hearty, warming meatless meal, served along with a crisp winter salad and sent to the table in all its molten glory.

Butternut Squash Panade

INGREDIENTS
2 Tbs butter
3 Tbs olive oil
3 medium onions, thinly sliced (about four cups)
Salt and pepper
4 cloves garlic, minced
2 tsp chopped fresh thyme
2 tsp chopped fresh sage
340g sliced stale country bread (if not quite stale, toast lightly and let cool before using)
450g butternut or other winter squash, peeled and sliced 0.6cm thick
230g Gruyere or Comte cheese, grated
4 cups water or broth, more as needed

METHOD
1. Heat oven to 180 deg C. Butter a deep 22-by-33cm baking dish and set aside.
2. In a large skillet, heat oil until sizzling over medium-high heat. Add onions and cook, stirring often, until softened, for about eight minutes. Season generously with salt and pepper. Continue cooking until onions are nicely browned for another five minutes. Stir in garlic, thyme and sage, then turn off heat.
3. Assemble the panade: Line bottom of baking dish with half the bread slices. Add a layer of cooked onions, then a layer of squash. Season squash with salt and pepper. Finish with a layer of grated cheese. Top with remaining bread slices.
4. Add water or broth and press down on the top layer of bread to make sure the casserole is evenly saturated. Add more if needed to soak the top layer. It should be damp, but not swimming in liquid.
5. Cover with foil, place on a sheet pan and bake, covered, for 45 minutes, until squash is tender. Uncover and bake 15 minutes more, until browned and bubbling on top. Let rest 10 minutes before serving.

Serves six to eight