Make Ahead Tip: Prepare the sauce (Step 4); cover and refrigerate for up to 1 day. Reheat just before serving.
Shopping Tip: Look for a squash with a long slender neck like a goose--at least 6 inches long and about 3 inches wide.
Tip: To toast chopped walnuts, heat a small dry skillet over medium-low heat. Add nuts and cook, stirring, until lightly browned and fragrant, 2 to 3 minutes.
1 starch, 1 vegetable, 2 fat