We roast acorn squash in a hot oven for deeply caramelized flavor, velvety texture and skin tender enough to eat, no need for peeling. While the squash is cooking, we whirl a simple vinaigrette in the blender to drizzle on at the end. It includes olive oil, sherry vinegar and orange zest and juice; the acids keep the flavors bright and balance the richness of the oil. Toasted pumpkin seeds blended into the dressing add a nutty flavor while also lending creaminess. This is the perfect side dish for fall and winter meals.