This can be done, but a kneading machine makes short work of the dough making. Proof the yeast in about 1/2 cup of milk and a tsp of the sugar. I always proof even instant yeast just to make sure the yeast is still active.
Whisk together the flour, and in the bowl of stand mixer or processor. In another bowl, whisk together the remaining milk, melted butter, sugar and egg. , egg, and egg yolks in a 4-cup measuring cup until sugar has dissolved.
Add the Tangzhong (if using), and the yeast mixture and start kneading. Now add the milk-egg-butter mixture and knead till a cohesive dough forms. After kneading the dough should be smooth and elastic. If necessary, add more flour, teaspoon at a time, to achieve this consistency.
Shape the dough into a ball, and place in a well-oiled bowl, turning to coat it uniformly. Cover loosely and let it rise till almost double, about 1 1/2 hours or so.