Sprinkle agar powder over 1/4 cup cold water and let it stand for 10 mins.
In the meanwhile, take orange juice, lemon juice and sugar into a saucepan and bring barely to a simmer. Do not boil the mixture. Keep stirring continuously. Taste the mixture and add more sugar if needed.
Remove from heat. Add agar + water mixture and whisk till agar powder is dissolved completely.
Remove panna cotta glasses from the fridge and pour the orange gelee mixture equally into all glasses leaving some room at the top to garnish.
Cover all glasses with plastic wrap and refrigerate for 2-3 hours or till the gelee is set.
Garnish with fresh strawberries and mint leaves just before serving!