Make the strawberry puree: Add strawberries, sugar, 1 cup water, and beet to a medium Stainless Clad Saucier or Saucepan. Heat over medium and cook, stirring occasionally, until very soft and fragrant, about 20 minutes. Remove from heat and let cool, about 5 minutes.

Strain strawberry mixture over a medium bowl, pressing on solids to extract liquid. Discard solids. You should have about 2 cups strawberry puree. Chill until cold.

Make the Tajín salt rim: Mix together salt and Tajín on a small plate. Rub rim of 2 Drinking Glasses with lime wedge and press rim into Tajín salt mixture.

Fill a cocktail shaker about halfway with crushed ice. Add tequila, orange liqueur, lime juice, and strawberry puree. Shake vigorously until outside of shaker is very cold, 15–20 seconds. Fill Drinking Glasses with ice and strain margarita into glasses. Cut a slit in bottom of each strawberry and place on rim of each glass to garnish.