1. In large bowl, combine warm milk and yeast; stir to dissolve.
2. Let stand until foamy, about 5 minutes.
3. Stir in warm water, butter, molasses, salt, whole-wheat flour, and 1/2 cup bread flour.
4. Stir in another 3/4 cups bread flour and knead mixture in bowl until a ball forms.
5. Transfer dough to lightly floured surface and knead until is smooth and elastic, 7 to 10 minutes.
6. Add additional flour just to keep dough from sticking.
7. Shape dough into ball and place in greased bowl, turning dough to grease top.
8. Cover with plastic wrap and then a towel and let rise in warm place until doubled in volume (about 1 hour).
9. Punch down dough.
10. Turn it onto lightly floured surface and knead in walnuts.
11. Cut dough in half; cover and let rest for 10 minutes.
12. (Resting makes the dough easier to shape).
13. Grease two large cookie sheets.
14. Shape each dough half into an oval and place on cookie sheets.
15. Cover loosely with plastic wrap and let rise until doubled (about 45 minutes).
16. With sharp knife or razor blade, cut three slashes across the tops of loaves.
17. Preheat oven to 375°F.
18. Lightly dust loaves with flour.
19. Bake until loaves sound hollow when tapped on bottom, about 30 minutes.
20. Transfer to rack to cool.