The fast food giant will test the P.L.T — plant, lettuce and tomato — burger for 12 weeks in Ontario, Canada. The trial starts on Sept. 30 and will be conducted in 28 stores. Beyond Meat Inc. stocks rose following the announcement. McDonald's shares also saw a modest rise. McDonald’s has a proud legacy of fun, delicious and craveable food — and now, we’re extending that to a test of a juicy, plant-based burger, Ann Wahlgren, McDonald’s Global Menu VP, via MarketWatch. McDonald's will cook the Beyond Meat patty on the same grill as their other burgers. McDonald's is the latest of a number of fast food chains that have begun to test a meatless option on their menu.