Warm the water, milk, and honey (or sugar) to about 125°F (52°C) or recommended temperature on the yeast packet. You can use a microwave or stove top for this. Ensure the temperature is correct using a kitchen thermometer to avoid killing the yeast. In the bowl of your stand mixer, combine the warmed water, milk, and honey (or sugar) mixture. Stir until the honey (or sugar) is dissolved. Sprinkle the instant yeast over the liquid mixture and lightly stir. Cover the bowl with a clean towel and let sit for about 5 minutes until it becomes foamy. This indicates that the yeast is active.
Add the softened unsalted butter and 1 cup of flour to the bowl.
Using the paddle attachment of your stand mixer, mix on low speed until mostly combined (the butter will still be a little chunky).
Gradually add the remaining flour, one cup at a time, to the bowl.
Mix on low speed after each addition until the dough starts to come together.
Switch to the dough hook attachment. Knead the dough on medium speed for about 8-10 minutes. The dough should be smooth and elastic. If the dough is too sticky, add a little more flour, one tablespoon at a time, until the desired consistency is reached.
Lightly grease a large bowl with oil or non-stick spray. Place the dough in the bowl, turning it to coat all sides. Cover the bowl with a clean kitchen towel or plastic wrap.
Let the dough rise in a warm, draft-free area for about 1-2 hours, or until it has doubled in size.
Once the dough has risen, gently deflate the dough and divide it into twelve pieces (about 80g each); to make smaller or larger buns see "tips," below. Shape each piece into a ball. Flatten each dough ball with the palm of your hand until it's about 3" across.
Place the buns on a lightly greased or parchment-lined baking sheet. Cover and let rise until noticeably puffy, about an hour.
Preheat your oven to 375°F (175°C).
Bake the buns for 15 to 18 minutes, until golden.
Cool the buns on a rack before slicing in half, horizontally.