Mix together the milk, 1 cup of water, 1 tbsp yeast, 1 tsp salt, and 1/4 cup honey, Add in 4 cups of bread flour, then the melted butter, and mix until all the flour is hydrated.
Reserve about 1/2 cup of oats. Add the remaining oats and pistachios to the dough, and work these ingredients into the dough by hand.
Turn the dough out onto a lightly floured surface and knead until smooth and springy, about 5-7 minutes. Push back any nuts that fall out of the dough. Cover the dough, wait 15 minutes, then knead again for 1-2 minutes.
Place the dough in a buttered bowl, and cover. Let rise in a warm place until about doubled, about 2 hours.
Gently remove the dough onto a floured surface, and divide into 2 portions. Form into round loaves, and roll reach loaf with the remaining oats.
Place each loaf into a bowl or banneton, cover, and let rise again for 30 minutes.
Pre heat your oven to 400 deg F. Place each loaf on a parchment-lined baking sheet, and score the center (this will help the bread to rise in the oven). Bake for 45 minutes or more until the surface is brown. Cool on a rack before slicing.