2. Place the butter in a large, deep skillet or Dutch oven over medium heat. When melted, add the onion and cook,stirring, until it softens, about 5 minutes. Add the nuts and cook, stirring almost constantly, until they begin to brown, about 3 minutes.
3. Add the bread crumbs and the sage and toss to mix. Turn the heat down to low. Add the salt, pepper, and scallion. Toss again; taste and adjust the seasoning. Add the parsley and stir. Turn off the heat. (At this point, you can refrigerate the stuffing in a covered container, for up to a day before proceeding.)
4. Place the stuffing in a casserole dish (3 quart or 9x13-inch) and bake for about 45 minutes, or until crisp and heated through.