This tea is finished with sweetened condensed milk, in yet another example of Singapore's propensity for fusing ingredients. To create a nice, frothy head, pour the tea back and forth several times between two cups before serving. Peel and finely grate one 7"-piece fresh ginger. Put ginger and all its juice onto several layers of cheesecloth; bring up edges to form a purse. Squeeze purse over a bowl, extracting as much ginger juice as possible (you should have 4–5 tbsp.). Discard purse. Put ginger juice and 1⁄2 cup sugar into a small pot and heat over medium heat just until sugar dissolves to make a syrup; let cool. In a pitcher, mix ginger syrup with 3 1⁄2 cups strongly brewed, strained black tea, such as assam, then add 1⁄2 cup milk and 1⁄4 cup sweetened condensed milk; stir well. Serve hot or over ice. Serves 4–6.