A thick cut of venison, covered in crispy onions and topped with a juniper berry sauce on a toasted bun, is about $5 at Arby's, if you can find one.

The fast-food chain, known best for its roast beef, Horsey Sauce and curly fries, is selling out of the sandwich within minutes in the 17 test markets across the country.

"We were very confident that hunters and even non-hunters would love this sandwich," Arby's spokesman Luke DeRouen told Nation's Restaurant News. "But it's safe to say that the response has exceeded our lofty expectations."

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The sandwich is being tested through November at select locations in Tennessee, Georgia, Minnesota, Michigan and Pennsylvania, all notable deer-hunting states.

It was released as part of the restaurant's "Meats Season" campaign, which corresponds with the start of hunting season.

Hungry customers gobbled them up in 15 minutes at the first test sites in Nashville.

It took 90 minutes for them to sell out in Atlanta.

The 120 sandwiches available at Michigan locations sold out in about 30 minutes, according to MLive.

DeRouen said officials thought they had given restaurants enough sandwiches for three days, according to CNBC.

The sandwich uses 100 percent free-range deer meat, from top and bottom round steaks off the hind quarter, Rob Lynch, Arby's brand president, told CNBC. It is marinated in garlic, salt and pepper and cooked for three hours. The sauce is a fusion of Cabernet steak sauce and juniper berries.

 "We're a brand that's not afraid to take risks and while the venison sandwich is probably the biggest stretch for us yet, it's incredibly delicious," Lynch said in a news release.