At Tillman's Roadhouse in Oak Cliff, Frito pie goes upscale with specialty ingredients and becomes Venison Frito Pie.

Come and listen to a story about mother love and Fritos.

Back in 1932, a year generally regarded as the nadir of the Depression, a San Antonian named C.E. "Elmer" Doolin tasted a home-fried corn chip in a Mexican cafe. He was so intrigued by its taste that he paid $100 for the chip's recipe and the right to market it.

Not that Mr. Doolin actually had $100 cash. He borrowed the money from his mama, Daisy Dean Doolin. Mrs. Doolin must have had an unshakable faith in her son, because she gave C.E. her diamond wedding ring to pawn for that $100 loan.

What's more, she let him set up shop in her kitchen and mix batch after batch of corn dough, which was shaped into strips by extruding the dough through a converted potato ricer. And she fried innumerable strips of ground corn in hot vegetable oil while C.E. and his brother, Earl, experimented with perfecting the chips. One can only imagine how many hours she must have spent scrubbing oil splatters from the walls and floor.

Mrs. Doolin's forbearance paid off. Thus was born the Frito (after the Spanish word for fried), an enormously successful snack product that celebrates its 75th anniversary this year.

But Mrs. Doolin took her sons' product one crucial step further.

According to corporate lore, Daisy Doolin invented the immortal Frito pie not long after her boys created Fritos.

Early on, says her granddaughter, Kaleta Doolin of Dallas, Daisy helped market Fritos by developing recipes that used the corn chips as an ingredient. In a burst of genius, she was inspired to pour chili over Fritos corn chips, and the rest is history.

Seventy-five years later, Fritos are more popular than ever, and Texans are still happily scarfing Frito pie everywhere from Tolbert's Restaurant to Tillman's Roadhouse.

Frito pie in Texas comes in versions ranging from the State Fair's in-a-bag snack to Austin-style hippie vegetarian dishes, and even in trendy wraps at Sonic Drive-Ins.

Never mind that Santa Fe claims Frito pie was invented there a mere 45 years ago.

Because we know better, you see.

What makes this dish a Texas classic?

At its heart, Frito pie is a simple concoction. In its primal form, even a child could make it. Like this:

Heat a can of Wolf Brand chili with beef, then take a small bag of Fritos, slit the bag open, and pour chili on top of the Fritos. Then eat it with a spoon right out of the bag as you walk around the State Fair of Texas or wherever you happen to be.

Frito pie, chili pie or chili-cheese pie: Whatever you call it, this is what Hemingway might call a moveable feast.

It's better, of course, if you sprinkle grated cheddar cheese on top. Some folks like their chili with beans, and some don't. If you like chopped onion, add that.

Some people pile on sour cream or jalapeños, too, although that begins to be something of a burden for one little Frito bag to bear. You might even have to move the bag to a plate. Which is allowable but frankly lacks street cred.

Granted, this is not a meal that a cardiologist would want you to consume every day. But, once in a while, Frito pie tastes really good.

How much more fundamentally Texas could it get? If Frito pie isn't enshrined in the Institute of Texan Cultures, it ought to be.

In 1933, the Doolin brothers moved the Frito Co. to Dallas, where it grew and prospered. In 1945, the Frito Co. granted H.W. Lay & Co. the right to franchise and distribute Fritos in the southeastern United States.

Two years after Herman W. Lay's death in 1959, the Doolins' Frito Co. merged with Lay's potato-chip empire and became Frito-Lay.

Pepsi-Cola and Frito-Lay then merged in 1965 and became part of PepsiCo, headquartered in Purchase, N.Y.

But Frito-Lay is still here; its sprawling corporate campus is on Legacy Drive off State Highway 121 in Plano.

In the Frito-Lay lobby, there is an oil portrait of C.E. Doolin commissioned last year by the founder's artist daughter, Kaleta. She spearheaded a family project to build the C.E. Doolin Four Seasons Garden as a gathering place for Frito-Lay employees, and it is filled with irises from her mother, Kitty's, garden.

Ms. Doolin is compiling a documentary film project on her father's life.

"It's my first real one," she says with a chuckle.

She has experimented with video art before and also works in other artistic media, while her husband, Alan Govenar, is a documentarian, author and playwright (Blind Lemon Blues).

Kaleta Doolin also contributed her family's Frito history to the Kitchen Sisters' next audio documentary series, Hidden Kitchens Texas, premiering in July on NPR's Morning Edition.

Like her grandmother Daisy, Ms. Doolin says: "I've carried on the family tradition, experimenting in the kitchen. I invented Frito Fondue. It's melted chocolate served with Fritos in a chip-and-dip tray. It's really good."

Sounds like a fitting memorial to Daisy Dean Doolin, the grandmother of Fritos and the mother of Frito pie.