Combine Margarita Mix, Tequila, and Grand Marnier then pour into a shallow metal baking dish. Cover with plastic wrap and place in the freezer for an hour.

Stir mixture, then freeze an additional 6 hours or overnight.

Scrap mixture with a fork creating the shaved ice. Store in freezer until ready to serve.

Serve in individual glasses rimmed with salt. Sprinkle with lime zest.