Begin by preparing the candied ginger, which will be used as a garnish for the drink. Peel and thinly slice 1 or 2 large fresh ginger roots, ideally using a mandolin for even slices. Place the sliced ginger in a large pot, add enough water to cover, and bring to a boil. Simmer for about 30 minutes, or until the ginger is tender.
Once the ginger is tender, drain it in a colander, reserving 1/4 cup of the cooking liquid. Weigh the drained ginger and measure out an equal weight of sugar. Return the ginger, reserved cooking liquid, and sugar to the pan. Set over medium-high heat and bring to a boil, stirring frequently. Reduce heat to medium and cook, stirring continually, until the syrup thickens, begins to dry out, and starts to recrystallize around the ginger slices (about 20 minutes).
Transfer the candied ginger immediately to a cooling rack, spreading the pieces apart so they do not stick together. Let them cool completely. Once cooled, the candied ginger can be stored in an airtight container for up to two weeks. I like to sprinkle a tiny bit of extra sugar on the ginger before storing for even more sparkle and crunch.
To make the margarita, combine 1/4 cup (2 oz) non-alcoholic tequila substitute, 1 tbsp plus 1 1/2 tsp (3/4 oz) freshly squeezed lime juice, and 2 tbsp (1 oz) ginger syrup in a cocktail shaker. Add ice to the shaker, then shake the mixture vigorously until the shaker feels frosty, about 5 to 10 seconds. I find that shaking just until the outside is icy cold gives the perfect chill and slight dilution.
Strain the cocktail mixture into a margarita glass or rocks glass filled with fresh ice. Garnish with a piece of candied ginger (from Step 3) and a lime wheel for a beautiful finish. For an extra elegant touch, try adding a dehydrated lime wheel or rimming the glass with chili-lime salt.