Forty Niner is truly a throwback diner, serving nostalgic comfort food and contemporary favorites.

Owner Wil Cordes has carried forward his predecessors’ recipes and added some of his own. He has expanded the once-tiny parking lot to accommodate more vehicles, added outdoor seating, and expanded the business with a second location in Wahiawa, as well as two lunchwagons that service Pearl Harbor Naval Shipyard. He doesn’t call them food trucks, just so you know.

About the business: Forty Niner was founded in 1947 by the parents of brothers Richard and Henry Chagami as a business for their sons, after they returned from their World War II service with the 442nd Regimental Combat Team.

Richard and other family members ran the restaurant while Henry kept the books until his death in 2004. Richard eventually sold the business to Cordes in 2006, but he retained some Chagami family members and the Forty Niner recipes for saimin, beef cutlet and other dishes, to keep loyal customers coming back.

For a time, Cordes’ mother, “Aunty Leilani” Cordes, worked in the diner. She would talk story with customers, Wilhelm “Wil” Cordes said, and if someone had an issue with their food she would try it, usually replying that there was nothing wrong with what they had ordered.

“Everybody here is a regular,” he said, nodding toward a group of lunchtime diners wearing neon shirts common among construction workers.

Cordes, whose background is in hotel food and beverage operations, wanted to open a Mexican restaurant, but when the Forty Niner location became available he took that opportunity to strike out on his own. The concept was strong enough to fuel his expansion to Wahiawa and to franchise a location in Japan. There is nary a quesadilla or taco on the menu.

Just as the Aiea location is itself a landmark, the Wahiawa restaurant has a landmark in front of it — a gas pump from 1927.

The menu: Keep in mind that portions are large, and that plate-lunch-style choices come with rice, spaghetti-mac salad, or tossed salad with a creamy but light dressing. Items range from $3.50 for a hamburger to $17.95 for a 10-ounce rib-eye with two eggs. A specials board invites customers to “make any burger ‘dirty’ for $1.50,” by adding tomatoes, grilled onions, deep-fried pickles and a creamy-tangy “dirty sauce.”

What to order: Most breakfast items are served all day, including impossibly thick Forty Niner pancakes served with haupia-macadamia nut sauce, or Elvis pancakes, made with bananas, layered with creamy peanut butter and topped with banana syrup, whipped cream and crispy bacon. Leftover haupia pancakes stored in the fridge end up almost like haupia cake.

Forty Niner originals include the beef cutlet ($10.95) — not deep-fried breaded beef but rather a mound of rib-eye steak sliced paper thin and grilled until cooked through and partly crispy. The beef is then topped with serious brown gravy and served with rice and tossed salad or spaghetti-mac.

Specials on a recent visit included grilled salmon for $10.95, or furikake salmon for $11.95.

Grab and go: About 75 percent of the business at Forty Niner is dine-in, with counter and table service at both locations. The Aiea location also offers outdoor picnic tables. The other 25 percent of the business is takeout. The Aiea spot has several parking stalls, and customers can park in the adjacent KFC lot. A shared parking lot is behind the Wahiawa location.