Expanding on EatChicago's reply, here are some margarita tips:
1. If you see any of these words on the margarita menu...
• Frozen
• Pitcher
• Slush(y)
• Blue (or any other color. Exception: gold)
• Mango (or the name of any other fruit. Exception: lime)
...quickly but calmly leave the premises. Proceed directly to the bar at Frontera and ask Craig to fix you the real thing.
2. Inquire whether the margaritas are made with anything other than the following:
• FRESH lime juice
• Good quality tequila
• Triple Sec, Gran Torres or other fine quality orange liqueur
• sugar (optional, but acceptable)
If the answer is yes, refer to the remedy in section 1.
3. What do they call their margaritas? Regrettably,
Strawberry Mojitorita, White Sangriarita and
Between the Hotel Sheets Margarita actually exist. If if you find one of these or something similar on the menu, you know what you must do. See section 1.
4. Better yet, just take EatChicago's advice and head straight to Frontera. Just not on Sunday or Monday; they're closed.