Beef and mushrooms are a winning combination. Served on a good steak, sautéed mushrooms add a complexity of flavor and savoriness. Mushrooms (often joined by Swiss cheese) make a great burger topping, too. It makes sense that adding ground mushrooms straight into a burger patty could create a tasty blended burger.

Sonic Drive-In is putting mushrooms right into their burger patties. This new menu item, the Sonic Slinger, rolled out this week, according to a company news release. Made from 25 to 30 percent mushrooms, the blended burger has less fat and fewer calories than an all-beef burger, along with a smaller carbon footprint.

The blended burger is not a new idea in the restaurant world. The James Beard Foundation began the Blended Burger Project in 2015, challenging chefs to create a better burger with at least 25 percent fresh, cultivated mushrooms, ground up and added to other burger ingredients. The project's aim is to get more burgers on menus that are healthier and less beef-heavy, adding nutrients like vitamin D, potassium and B vitamins to burgers via mushrooms, and encouraging sustainability.

Sonic, however, is the first major fast-food chain to sell a burger made of combined beef and mushrooms. The Slinger comes on a brioche bun with either mayo, onions, lettuce, tomato, pickles and cheese, or bacon, mayo and American cheese.

Mushroom for improvement

I'm curious about the Slinger. If the company tests the blended burger at a store near me, I'll probably go check it out and see if they've been able to create something delicious. Some people in the focus groups who have already tasted the burger say it's better than the all-beef version. If this goes well, and other fast-food and fast-casual restaurants create their own versions, it could make a significant dent in the amount of beef consumed.

With about 25 percent less beef in the patty, plus a filler that's tasty and nutritious, burgers like these are a promising way to curb beef production and consumption. A burger that's one-quarter mushroom can make a big difference environmentally. Producing a pound of mushrooms requires about 0.7 pounds of carbon dioxide emissions, according to a recent study, while the carbon footprint for a pound of beef is 12.3 pounds, making beef one of the most carbon-intensive foods we eat.

If you don't want to wait for Sonic to roll out its blended burgers, some of the participating restaurants in the Blended Burger Project may have their burgers on the menu right now. Call ahead to confirm.

Editor's note: This story was originally published in June 2016 and has been updated with more recent information.

Robin Shreeves ( @rshreeves ) focuses on food from a family perspective from her home base in New Jersey.

Fast-food restaurant rolls out 'blended burger'
By making patties from beef and mushrooms, Sonic is reducing the carbon footprint of its burgers while adding nutrition.