Whisk the flour and almond milk in a saucepan over medium-low heat. It will go from thin to thick quickly. Stop when it looks like a smooth paste and a spoon leaves trails that hold for a second.

In a large bowl, stir the tangzhong with the remaining almond milk until mostly smooth. Touch the mixture. It should feel warm, close to body temperature, not hot.

Stir in the all-purpose flour, whole wheat flour, sugar, and instant yeast. It will look rough and shaggy at first.

Mix until the dough turns cohesive. It may feel slightly tacky but should not be wet.

Knead on a lightly floured surface until smooth and elastic. The dough should stretch without tearing and slowly spring back when pressed.

Place in a lightly oiled bowl, cover, and let rise until doubled. The surface should look puffed and relaxed.

Press dough into a rectangle, then roll it tightly from the short side to keep the crumb even. Place seam-side down in a greased 9 x 5 pan (parchment strip helps).

Cover and rise until the dough is about 1 inch above the pan. A gentle fingertip press should fill back slowly.

Bake at 400°F / 200°C until deep golden and it sounds hollow when tapped.

Cool at least 15 minutes, then remove from pan and cool fully on a rack before slicing for the cleanest slices.