This colorful salad of sweet, soft roasted squash and crisp, bitter greens finished with a creamy, tangy green goddess dressing is an elegant mix of contrasting flavors and textures. The squash is good both warm and at room temperature, so feel free to roast it ahead of time. Some bitterness is nice against the sweet winter squash, but if you want to mellow radicchio’s bite a bit, you can soak the pieces in ice water for 10 to 30 minutes, then drain and dry before adding to the salad. Just taste before you soak; you’ll want a little bit of its bitterness. The dressing will keep for at least three days in the fridge. Serve it over other salads, or as a dip for cut-up vegetables and chips.