Combine strawberries, 3 watermelon chunks, and 2 mint leaves in a cocktail shaker. Press against bottom and sides of shaker using a muddler or back of a wooden spoon to release flavors; add tequila, blood orange liqueur, Jalapeño Honey Syrup, and a dash of sea salt. Fill shaker with ice; cover with lid and shake vigorously until thoroughly chilled (about 30 seconds). Strain into a tall, ice-filled glass; top with club soda. Garnish, if desired.
Seanachai Social Club, Johns Island, South Carolina; seanachaisocialclub.com