Churn liquid in an ice cream machine for 15-20 minutes or until frozen. Transfer to freezer until needed.
For orange syrup, place remaining 100g sugar and orange juice in a saucepan and simmer till reduced by half. Strain through a fine sieve and chill for 1 hour.
From remaining punnets, slice grape tomatoes in half lengthwise and half fill 30 shot glasses. Top with a tsp of sorbet and drizzle with orange syrup. Garnish with basil leaves.