Prepare the Boba: Bring 4 cups of water to a rolling boil in a medium saucepan. Add the dried tapioca pearls and stir immediately to prevent sticking.

Cook the Boba: Reduce heat to medium-low and cook the boba according to package directions, typically 10-15 minutes, until they float and are soft and chewy in the center.

Prepare the Syrup: While the boba cooks, combine 1/4 cup brown sugar and 1/4 cup water in a small pot. Heat until the sugar dissolves completely, creating a simple syrup. Set aside.

Soak the Boba: Once cooked, drain the boba immediately and rinse briefly with cold water to stop the cooking process. Transfer the drained boba into the brown sugar syrup and let them soak for at least 10 minutes to sweeten and soften further.

Assemble the Tea Base: In a large pitcher or mixing bowl, combine the chilled black tea, strawberry puree, and sweetener. Stir well until the sweetener is dissolved.

Build the Drinks: Divide the sweetened boba pearls and syrup evenly between two tall glasses. Fill each glass generously with ice cubes.

Finish and Serve: Top each glass with the strawberry tea mixture, then slowly pour in the milk over the top. Stir gently before serving with a wide straw.