Place a rack in bottom third of oven; preheat to 425°. Place ½ medium butternut squash (1½–2 lb.), peeled, seeds removed, cut crosswise 2" thick, 1 medium acorn squash (about 1½ lb.), scrubbed, halved, seeds removed, cut into 2"-thick wedges, and 1 small delicata squash (about 1 lb.), scrubbed, cut into 2"-thick rings, on a large rimmed baking sheet; drizzle ¼ cup extra-virgin olive oil over and sprinkle with a generous pinch of kosher salt. Toss to coat; arrange in a single layer. Roast squash, undisturbed, until almost completely tender (about three quarters cooked) and deep golden brown underneath, 25–35 minutes.

Meanwhile, bring one 1" piece ginger, peeled, finely grated, ½ cup apple cider vinegar, ½ cup pure maple syrup, ¼ cup low-sodium soy sauce, 2 Tbsp. sambal oelek, and 2 Tbsp. white miso to a boil in a medium nonstick skillet over medium heat and cook, whisking often, until glaze is thick and syrupy, 7–9 minutes.

Remove squash from oven and pour glaze over; shake baking sheet gently to distribute glaze as evenly as possible (it doesn’t have to be perfect). Return to oven and roast until squash are completely tender and glaze is sticky, 12–18 minutes. Gently toss squash to coat well in glaze; transfer to a platter.

Meanwhile, cook 2 bunches scallions (about 16), thinly sliced on a diagonal, and remaining ¼ cup extra-virgin olive oil in a medium nonstick skillet over medium heat, stirring often, until scallions are deeply browned in spots and crisp, 8–12 minutes.

Spoon scallions over squash, leaving most of the oil behind (save for another use, like frying eggs or spooning over rice). Scatter 1 large Fresno chile, thinly sliced, on top if desired.