The word "strata" is plural for "stratum," or layer of sedimentary rock. In food terms, the word strata is appropriate for the layers of ingredients and flavors in a casserole of bread, eggs, milk, vegetables, meat and cheese that constitute a one-bowl meal.

We often think of strata as a breakfast or brunch dish, but who says it can’t be served for lunch or dinner? After all, there’s a carbohydrate (bread), protein (eggs, milk, meat and cheese) and vegetables (greens, mushrooms, onions, peppers). The beauty of a strata extends beyond the delicious combination of ingredients.

First, the ingredients can and should be prepared ahead of time. Soak the bread in a custard mixture comprising the eggs and milk; saute or blanch vegetables; cook sausage; grate cheese. Have the layers ready to assemble; you could do this a day or two before cooking.

Second, you can use whatever happens to be in your refrigerator, no special ingredients required. Substitute sausage with bacon or ham; use kale or bok choy; use leftover bits of cheese and bread.

Third, a strata can be served hot or at room temperature, making this a great do-ahead dish for any meal or potluck. It’s always perfect for a breakfast or brunch since you can prepare it the night before.

Strata is essentially a savory bread pudding, relying on a custard to hold it together. As with a sweet bread pudding, bread is soaked in a mixture of egg and milk and, when baked, it becomes a seamless, somewhat dense, creamy textured, cakelike product. Soaking the mixture of bread, eggs and milk for several hours or overnight is key to a delicious strata.

Bread that is less than fresh is perfect for this dish. All those bits of croutons, crusts, crumbs and leftover slices in your freezer can be used up, or you can buy a good crusty country loaf or baguette.

The custard mixture comprises egg and milk, basically a proportion of 1 egg to 1/2 cup milk. The milk can be skim, 2 percent or whole; milk with fat will make for a richer dish. Or you could use half-and-half or cream for an ultra silky strata. Replacing an egg with two egg yolks will also raise the creaminess factor.

Now comes the fun part: the savoriness of a strata. These are all the flavor-filled ingredients that are layered to form the casserole. Start with proteins: a favorite sausage, maybe Portuguese, Italian, chorizo, bratwurst, bulk pork, kielbasa or andouille. Bacon, pancetta, prosciutto and ham are good candidates as well. Smoked salmon would make an elegant strata.

Choose just one, cut into 1/2-inch cubes, and saute in a frying pan. Drain off any excess oil before adding to the casserole.

Next, add a vegetable or even two. Clean and chop leafy greens such as kale, chard, spinach, bok choy, arugula, asparagus or other favorites that you find fresh at the farmers market. Saute in a little olive oil, and season with salt and pepper. Or blanch the vegetables in boiling water until wilted. Cool vegetables, then squeeze out any liquid to prevent custard mixture from being diluted.

Mushrooms are in the vegetable category, too; a vegetarian strata could include a medley of Hamakua-grown mushrooms. Add a bit of color with sauteed red bell peppers, roasted peppers or pimentos from a jar; roasted or sun-dried tomatoes will add another flavor dimension. Artichoke hearts, cooked potatoes or green beans add good texture to a strata.

Always include sauteed onion for its sweet but savory flavor. Fresh herbs such as parsley, chives and thyme are good additions as well.

All the elements — meat, vegetables, onion — are cooked separately before assembling.

Finally, choose a cheese. Sharp cheddar is always good; consider mixing it with a milder, creamy Monterey jack. Fontina and harvarti are excellent, and Parmigiano-Reggiano sprinkled over the top will brown and crust nicely.

Employ cheese as another flavor element, used as a layer in the middle and on the top, but restrain yourself from making this a gooey, cheesy casserole.

Sometimes I plan a strata, especially when it will be a centerpiece of a party. But at other times, a strata can be the perfect way to incorporate leftovers from the refrigerator. Have a few strips of leftover bacon or a few slices of Portuguese sausage? Maybe a serving or two of sauteed mushrooms or vegetables? Bits and pieces of cheese waiting to be used up?

In this case, an impromptu strata can be assembled in individual portions. Soak bread in the custard mixture in a bowl, then scoop the mixture into small casseroles or ovenproof bowls and layer in other ingredients.