Step 1

Place a rack in middle of oven and preheat to 350°. Toss summer squash, garlic, lemon zest, thyme, oil, and salt in a shallow 2-qt. baking dish to combine.

Step 2

Turn garlic cut side down, then roast vegetables, tossing 2 or 3 times, until golden brown, very tender, and edges and cut sides are crisp, 1 hour and 40 minutes–1 hour and 50 minutes. Let cool slightly, then add lemon juice and toss to coat.