This is a bigger deal than the McRib. Bigger than McNuggets or McFlurries. Don't even get me started on Filet O'Fish.

McDonald's is testing out a new sandwich in Canada that could fundamentally alter how we look at both the world's most iconic burger brand and plant-based burgers. 

It's called the P.L.T., which stands for plant, lettuce, tomato. No bacon here, to be sure. 

Yes, all three parts of the name are plants, but let's not be too critical of the branding before it even gets off the ground. 

The P.L.T. is your basic burger on a sesame seed bun, but with a variation of Beyond Meat's plant-based patty that the company says was crafted exclusively for McDonald's to mimic the fast food chain's "iconic taste."

This writer's opinion of that iconic taste not withstanding, a vegan burger option at McDonald's is potentially a revolution for both fast food and plant-based meats. We've seen the Impossible Burger on Burger King's menu, plant-based meatball subs at Subway, and even Beyond Chicken at KFC, but it doesn't get more mainstream than Mickey D's (and I have yet to actually see plant-based meat on a Subway menu in the real world).

There are over 38,000 McDonald's locations in over 100 countries. The market and branding potential is just enormous.

"During this test, we're excited to hear what customers love about the P.L.T. to help our global markets better understand what's best for their customers," said Ann Wahlgren, McDonald's VP of Global Menu Strategy. "This test allows us to learn more about real-world implications of serving the P.L.T., including customer demand and impact on restaurant operations."

A full list of the locations where the P.L.T. will be available in Ontario starting Monday is here. It will be available for the equivalent of less than $5 in the U.S. 

How soon until we might actually see it on a McDonald's menu in the U.S. is another matter altogether. It's all in the hands of Canadian P.L.T. eaters now.