Lightly crush the cardamom pods with the side of a knife or mortar and pestle to release their essential oils.

Heat a small saucepan over medium heat for about 1 minute until warm, then add the cloves, cardamom, peppercorns, cinnamon stick, and star anise and toast, stirring constantly, for 2 to 3 minutes until fragrant.

Pour in 4 cups of water and add the ginger slices, then bring the mixture to a boil over medium-high heat.

Reduce the heat to medium-low and simmer gently, uncovered, for 10 minutes to concentrate the spice flavors.

Remove the pan from heat and add the tea bags or loose tea, then steep for exactly 5 minutes, stirring occasionally.

Strain the mixture through a fine mesh strainer or cheesecloth into a heatproof bowl, pressing gently on the solids to extract remaining liquid.

Stir in the honey or agave syrup and a pinch of sea salt while the concentrate is still warm until fully dissolved.

Let the concentrate cool to room temperature, about 15 to 20 minutes, then transfer to glass bottles or jars, seal tightly, and refrigerate immediately.