When a restaurant or other food establishment closes, often the signature recipes are gone forever.

We may never again taste the chocolate-chip loaf from Hesh's Bakery or the German chocolate cake from Rindelaub's, to name two famed carbohydrates that Philadelphians grew up with.

It was the closing of Hesh's that inspired reader Kate Dolan to email, asking if I could track down the recipe for H.A. Winston & Co.'s French onion soup.

Perhaps some back story is in order: Winston's, a force in the Philadelphia area's casual dining world from 1972 to 1992, was the precursor to a series of Americana-themed fern-bar chains, such as Bennigan's, Houlihan's and T.G.I. Friday's.

By 1977, according to an Inquirer story, there were 22 locations, both owned by the company and by franchisees.  The last one - at 15th and Locust Streets - closed in 1992.

Winston's was known for its curio-filled decor and its juicy burgers but it was the onion soup that was the real hit. Served in an earthen crock, it was a cauldron of sauteed onions in a beefy broth. On top floated a giant crouton, buoyed by a layer of molten cheese that bobbed almost menacingly.

Finding the recipe turned out to be a snap. I reached out to publicist Dallyn Pavey, who represents Hope's Cookies in Bryn Mawr, whose co-owner is Herb Spivak - the "H" in H.A. Winston's. (Brother Allen Spivak was the "A.")

Dallyn worked for Winston's in Bryn Mawr, it turns out.

Herb, who also had a hand in Electric Factory Concerts, was sweet enough to provide a home-scaled version of the French onion soup that is just like the original.

The recipe calls for Lipton's onion soup mix. Lipton's onion soup mix? The base of a thousand brisket recipes?

"It was originally made with Lipton's at the Front and Chestnut location," Dallyn explains. "They were first baked in a toaster oven. Herb later fashioned the recipe from Lipton's ingredients and had it manufactured for Winston's. They would make up 25-pound bags of the mix for him."

Turns out that two other secrets were the use of Gravy Master (a sweet seasoning sauce your mother probably used) and the specific layering of the cheeses.

This recipe will make six generous servings.

H.A. Winston's Onion Soup (for home use)

4 medium size sweet onions

1/4 teaspoon Gravy Master

2 packs Lipton's Onion Soup Mix

slices of crusty Italian bread, 1/2-inch thick, toasted

slices of provolone cheese and either Gruyère or imported Swiss cheese

Salt and pepper to taste

Peel and slice onions with the grain (not against grain as you would if cutting for sandwiches) in about 1/4 inch width the full length of the onion.

Put the onions in approximately 1 1/2 quarts boiling water.

Add Gravy Master.

Boil at medium heat for about 45 minutes, until the onions are somewhat translucent.

Add Lipton's Onion Soup Mix (do not cover the pot).

Simmer for 30 minutes.

Ladle a portion of soup, heavy with the onions, into serving crock.

Cover crock with 1 slice of toasted Italian bread, 2 slices of provolone cheese and 1 slice of Gruyère or imported Swiss cheese.

Placement of cheese:

Put the Swiss in the middle of the 2 slices of provolone.

Put under broiler (about 6 to 9 inches from heat).

When cheese turns dark and it starts to melt, wait a minute and take from broiler.

It's ready to enjoy.