Naturally bitter radicchio mellows when grilled -- and pairs perfectly with colorful yellow and pattypan squashes in this healthy dish.
Preheat grill to medium-high. Arrange vegetables in asingle layer on a rimmed baking sheet. Brush generouslywith oil, and season with salt and pepper.
Grill vegetables until just tender and slightly charred: about 3 minutes for the scallions, 4 to 5 minutes per side for the squashes, and 10 minutes total for the radicchio, flippingevery 2 minutes. Squeeze lemon halves over vegetables.