Let the mint steep in the brewed tea for 30 minutes. Add the sugar syrup to make it very sweet. Add lemon juice to bring back the tea flavor and to reduce the sweetness. Freeze in an ice cream machine according to manufacturer's instructions.Simple Syrup:
In a saucepan, combine sugar and water. Bring to a boil and simmer until sugar is dissolved, but no color is reached. Remove from the heat and let cool.