Ontario

You must admit, the current Onatrio flag is quite complex, along with that super-complex Union Jack. And since Canada is independent from the United Kingdom, their provinces could help display that fact by removing the Union Jack from their flags.

In this design, I a red background with a white cross. The red and white are the colors of Canada, and the cross hints at the United Kingdom, but doesn't scream it like the real flag. I took the green shield with leaves and transformed it into a canton for this design, and the result looks as Ontarioan as anything.
A masterpiece, if I do say so myself.