Subway has begun to test the plant-based protein waters, announcing a partnership with Beyond Meat to bring a meatless meatball sub to its menu next month.

This September, Subway will be adding a “Beyond Meatball Marinara” sandwich to 685 menus in Canada and the U.S. for a limited time. The sandwich is similar to the QSR’s Meatball Marinara sub, with the meatballs substituted with plant-based ones made from Beyond Meat’s plant-based formula.

The LTO is a test of how plant-based offerings could be incorporated into Subway’s menu, with the company saying in today’s announcement that it is the start of an exploration, without saying if it had any other products planned, or what they might be.

In addition to serving demand for plant-based menu items (the QSR cited NPD Group research claiming 70% of meat eaters now substitute one plant-based meal a week), Subway said in the announcement that it is also part of the QSRs ongoing goal of providing “food experiences” they can only get at Subway. Beyond Meat developed the “Beyond Meatball” with Subway, and for the time being it will only be available there.

“Subway appeals to so many fans because we truly offer something for everyone,” said Len Van Popering, Subway’s chief brand and innovation officer. “Our guests want to feel good about what they eat and they also want to indulge in new flavours. With our new plant-based Beyond Meatball Marinara sub, we are giving them the best of both worlds. And, we are particularly excited about debuting a co-developed product that can’t be found anywhere else.”

The last year has seen a flurry of activity from QSRs and other food companies looking to answer consumer demand for plant-based protein options in their meals, with many of them doing so by incorporating Beyond Meat into their menus.

In its Q2 financial results, released last week, Tim Hortons parent company Restaurant Brands International pointed to the introduction of Beyond Meat breakfast sandwiches as being among the new offerings that helped it beat analyst expectations, with the QSR recently tapping the company for its first foray into the burger category. Same-store comparable sales were up 0.5% at Tim Hortons in Q2 (which also pointed to store remodellings and the new loyalty program as contributing factors to its performance), while sister company Burger King (which introduced a burger from plant-based rival Impossible Burger this year) saw sales growth of 3.6%.

Other companies are looking to compete with Beyond Meat, instead of working with it. Maple Leaf previously acquired U.S. plant-based brand Lightlife, launching the new Lightlife Burger across North America earlier this year to compete with Beyond Meat on store shelves. Maple Leaf Foods announced 12.5% sales growth in Q2 last week, with CEO Michael McCain pointing to its ability to serve demand for plant-based proteins as part of the reason for the growth.