Bring 4 cups of water to a boil, remove from the heat and add the tea bags or loose leaves. Allow the tea to steep for 5 minutes.

Meanwhile, purée the peaches if using fresh fruit. Pulse in a food processor or blender until very smooth. You should have 2 cups.

Gently squeeze the concentrated tea from the bags and discard the bags. If using puréed peaches, pour the tea into the food processor, add the lemon juice, and purée until smooth. Transfer to a pitcher. If using peach juice, transfer the tea to a pitcher, and stir in the peach juice and lemon juice.

Add the ice to the pitcher, then taste. If it’s too sweet, add more lemon juice and if it isn’t sweet enough, stir in sugar, 1 teaspoon at a time, until dissolved. Refrigerate until the tea is chilled throughout, about 2 hours. Serve in a large glass filled with ice and garnished with peach slices and fresh mint.