Bring 7 cups of water to a boil, targeting about 90–95°C (195–203°F). Remove from heat, add the black tea bags, and steep for 2½–3 minutes maximum — do not oversteep.
Remove the tea bags without squeezing. Let the tea cool until just warm or room temperature.
Stir the lemon juice and honey into the lightly cooled tea until fully dissolved.
Add the clapped mint leaves and the lemon zest (outer yellow layer only). Refrigerate and let infuse for 10–15 minutes, then remove and discard both mint and zest to avoid bitterness.
Continue chilling the tea until fully cold, about 1–2 hours.
Fill glasses generously with ice. Pour over the chilled lemon mint iced black tea and garnish with fresh lemon slices and mint leaves.