An occasional series in which staff members share a recipe that we turn to time and again:

After 10 years, our family has finally left elementary school. But we're keeping the strata.

For most of that time, a Sausage, Gruyere and Onion Strata was the centerpiece of a brunch we offered for bid at Woodlin Elementary's winter festival in Silver Spring. My wife would make a selection of breakfast breads and a fruit salad; I contributed jalapeno-cheese grits and the strata.

A strata is a custardy egg casserole that has several things going for it: It is best when assembled the night before. It puffs up golden brown like a souffle -- more impressive than it should look, given the little work required. And when it comes out of the oven, it smells like the gates of heaven have opened.

Who knows if silent-auction winners really like the food you make for them (a pitcher of Mimosas always puts them in a good mood). But the same family has won the strata two years in a row. And this year, knowing it was our last, they asked for the recipes.

Sausage, Gruyere

and Onion Strata

6 to 8 servings

If you prefer, you may use chopped, fully cooked smoked sausage instead of fresh sausage. Since that kind of sausage needs no cooking, saute it with the onion to blend the flavors. I usually make 11/2 times this recipe, which works well, to make sure there's enough for eight.

From "The Good Egg," by Marie Simmons (Houghton Mifflin, 2000):

8 ounces breakfast, sweet Italian or other sausage, casings removed

1 tablespoon extra-virgin olive oil, plus additional for the casserole

1/2 cup chopped onion

1/2 cup chopped red bell pepper

1 clove garlic, minced

2 tablespoons chopped fresh flat-leaf parsley

1 teaspoon kosher salt, plus additional to taste

Freshly ground black pepper

5 large eggs

21/2 cups milk

6 to 8 thick (1/2-inch) slices firm white sandwich, Italian or French bread, preferably 1 day old

11/2 to 2 cups grated Gruyere cheese (about 6 ounces)

In a large skillet over medium heat, heat the sausage, stirring frequently with a wooden spoon or spatula to crumble it into pieces, until lightly browned and no trace of pink remains, about 5 minutes. Transfer the sausage to a strainer set over a bowl and set aside to drain; discard any fat. Wipe out the skillet.

Return the skillet to medium heat and add the oil. Add the onion and bell pepper and cook, stirring, until golden, 8 to 10 minutes. Add the garlic and cook for 1 minute. Stir in the parsley, a pinch of salt and a grinding of pepper. Add the sausage and stir to combine. Set aside.

In a large bowl, whisk the eggs until foamy. Whisk in the milk until blended. Add 1 teaspoon salt and a grinding of pepper.

To assemble the strata, lightly coat a 2-quart shallow baking dish with oil. Use half the bread slices to make a single layer in the baking dish, cutting them, if necessary, to fit tightly. Spoon the sausage mixture evenly over the bread. Sprinkle with 1 cup of cheese. Use the remaining bread slices to make a second layer, once again cutting them to fit if necessary. Pour the egg mixture evenly over the top, using a spatula to press on the bread so the liquid is evenly absorbed. Top with the remaining cheese. Cover with plastic and refrigerate for at least 4 hours or up to overnight.

Preheat the oven to 350 degrees. Uncover the strata and bake until puffed and browned, about 45 minutes.

Per serving (based on 8): 358 calories, 19 gm protein, 18 gm carbohydrates, 23 gm fat, 183 mg cholesterol, 9 gm saturated fat, 781 mg sodium, 1 gm dietary fiber

Robert Barnes is The Post's Metropolitan editor.