Remember when the Big Mac was the ultimate “grownup” burger on the McDonald’s menu?

So why is this sandwich so caloric?

“Well, since you asked, what’s in the sauce ,” Blais cheekily said.

McDonald’s Big Arch burger on yellow background

Photo: McDonald’s. Design: Eat This, Not That!

“I can’t give away all my secrets just yet Richard!”

All the signs seem to be pointing to the sandwich making its U.S. debut some time soon.

McDonald’s Big Arch burger

McDonald’s Canada