In a 4-quart pot over high heat, combine 1 3/4 cups water; 2 1/4 cups sugar; 4 whole cardamom pods; 3 whole star anise; and 3 cinnamon sticks. Cover and bring to a boil, then reduce heat to medium-low and simmer 10 minutes.
Remove tea bags and spices with a slotted spoon and add 8 cups whole cranberries (about 2 1/2 bags, fresh or frozen). Increase heat to medium-high and simmer, stirring often, until cranberries soften and split their skins and sauce thickens, about 12 minutes.
Remove from heat and let cool to room temperature before serving (the sauce will thicken further as it cools). Or cover and refrigerate up to 4 days.
