In a small saucepan, whisk together milk and flour. Cook over medium-low heat, whisking constantly, until mixture is thickened, an instant-read thermometer registers 149°F (65°C), and whisk leaves lines on bottom of saucepan. Transfer to a small bowl, and let cool to room temperature before using.
Recipe by Bake from Scratch at https://bakefromscratch.com/small-batch-four-cheese-pull-apart-milk-bread/