In a small saucepan, whisk together milk and flour. Cook over medium-low heat, whisking constantly, until mixture thickens and registers 149 °F (65°C) on an instant-read thermometer and whisk leaves lines on bottom of saucepan. Transfer to a small bowl, and let cool to room temperature before using.
Notes
We used King Arthur Bread Flour
Recipe by Bake from Scratch at https://staging.bakefromscratch.com/tangzhong-secret-behind-japanese-milk-bread/