Heat water in a small saucepan until bubbles start to form around the edges. Add tea bags. Reduce heat to a simmer.
Lightly crush lump sugar, ginger, cinnamon, rose buds, and cardamom pods in a mortar. Stir into the pot. Simmer until the tea bags and spices have become saturated, about 3 minutes. Add evaporated milk. Stir and simmer, without boiling, until sugar has dissolved and tea reaches the desired strength, about 8 minutes for strong tea. Strain into mugs.