Musky cantaloupe stands up to tarragon's assertive aniselike flavor in this palate-cleansing treat.
Process cantaloupe and 2 tablespoons water in a food processor until smooth, about 2 minutes. Transfer to a large bowl. Stir in lemon juice and syrup.
Pour mixture through a fine sieve into another large bowl; discard solids. Freeze in an ice cream maker according to manufacturer's instructions. Transfer sorbet to an airtight container; freeze at least 4 hours or up to 1 week before serving.