In the southwestern cities where Z'Tejas serves these incredible margaritas, they are truly legendary. The secret mixture is made fresh every day in a freezing dispenser machine with a dirt-cheap brand of tequila and custom-made sweet-and-sour mix. Perhaps that's the beauty of the drink. It's one of the most potent margaritas around, but with the addition of sweet liqueurs, its strength is well hidden. Even though the chain uses a special machine to make this one, preparing your own clone doesn't require any special equipment. It does take patience, however. Most good things do. But before long you'll be enjoying either a clone of Z' Big Stick with three layers of liqueurs, or a copy of the Famous Chambord Raspberry Margarita, the drink that earns "Best Margarita in Town" awards for the chain on a regular basis. 

You can, of course, drink the basic margarita base without the liqueurs, but the added liqueurs give the drink its charm. To create the margarita, you must mix all the ingredients in a pitcher and put it in the freezer for at least 4 hours, even overnight if you can. The cocktail won't freeze solid since there's tequila in there. When it's frozen, you take it out, and give it a little stir until it's the perfect slushy consistency.

This recipe clones the tall, 14-ounce drink served in a pilsner glass with layers of Chambord, Midori, and blue curacao. The restaurant limits customers to just two of these drinks per visit. Try it and you'll find out why.

Source: Top Secret Recipes: Sodas, Smoothies, Spirits & Shakes by Todd Wilbur.