. >> reporter: isabelle custer and her staff came all the way from her france to see how they'll manage the rollout of a new burger they call they the mcfarmer. >> it's a product made with salad, tomatoes and they're looking into the kitchen to see if we have the capacity to do that on the top of existing product. >> reporter: they want to be sure that making this burger doesn't screw up the process of making everything else, and the only way to to that is to test is in the fully functioning kitchen staffed with mcdonald's workers and filled with tips people paid to come and order and eat for the day. so you literally, you ordered -- you timed the exact orders. >> yes. >> reporter: and they go to the counter to see if the counter can handle it. >> yes. it's interesting because we can see everything. >> reporter: they rebuilt this restaurant to match french restaurants, believe it or not, have bigger kitchens because they have huge lunch crowds there with huge orders. >> in france, you have to build our kitchen like a ferry. you understand that? in the u.s., they have soup products. in f