In a medium saucepan, bring 4 cups of water to a gentle boil.
Add the dried hibiscus flowers and simmer for 5 minutes.
Remove from heat and let steep for another 10 minutes for a deeper flavor.
Strain out the hibiscus flowers and let the tea cool to room temperature.
Stir in the coconut milk and sweetener until well blended.
Pour over ice in glasses and garnish with lime slices or mint leaves if you like.