Heat milk and water in microwave for 45 seconds. Add to bowl of a stand mixer with honey and then sprinkle yeast on top. Let sit for 10 minutes until yeast activates (becomes foamy).
Meanwhile, mix flours, salt, and oats together in a bowl.
Once yeast has activated, add butter to mixer bowl and with the dough hook attachment, beat on medium low. Slowly add flour and oats mixture and beat until a sticky dough ball forms.
In a lightly greased large bowl, add the dough ball. It will be sticky. Cover with a linen towel and let rise until doubled (about an hour). If your house is cold and your oven has a "proof" setting, this works well too.
Pre-heat oven to 400 degrees.
Once doubled, punch down our dough and transfer it to a lightly floured surface. Flatten dough into a large rectangle and then fold the sides up into itself then roll the end closest to you away from you, rolling your dough up into a log.
In a greased 9 x 5 loaf pan, add dough seam side down and cover with towel again and let rise for another 30 minutes.
On the medium rack, bake for 20 minutes and then turn. Bake for another 20 minutes. Dependent upon your oven, check to ensure it's not burning. You want a nice deep browning but not burning.
Remove from oven and transfer to cooling rack to cool. To check to see if the center is cooked, give the bottom of the loaf a little tap. It should sound hollow.
Slice and enjoy!