Preparation Scrape stems, seeds, and veins from jalapeño into a small jar (reserve green flesh for another use). Add tequila; cover and let infuse for 15 minutes. Set a strainer over a small bowl. Pour tequila through strainer and discard solids. Place watermelon cubes in a large pitcher. Using a muddler or potato masher, coarsely crush watermelon. Stir in lime juice, Simple Syrup, mezcal, and jalapeño tequila. Stir in 2 cups ice. Cover and refrigerate until chilled, about 2 hours. Fill Old Fashioned glasses with ice. Divide cocktail among glasses and serve.
Preparation Scrape stems, seeds, and veins from jalapeño into a small jar (reserve green flesh for another use). Add tequila; cover and let infuse for 15 minutes. Set a strainer over a small bowl. Pour tequila through strainer and discard solids. Place watermelon cubes in a large pitcher. Using a muddler or potato masher, coarsely crush watermelon. Stir in lime juice, Simple Syrup, mezcal, and jalapeño tequila. Stir in 2 cups ice. Cover and refrigerate until chilled, about 2 hours. Fill Old Fashioned glasses with ice. Divide cocktail among glasses and serve.