Step 1

Preheat oven to 425°. Coat a rimmed baking sheet with 1 Tbsp. oil. Mix garlic, salt, Aleppo-style pepper, and 3 Tbsp. oil in a large bowl. Add cabbage, onion, and squash and toss to coat. Spread out on prepared baking sheet (keep bowl handy) and roast until squash is browned underneath, 25–30 minutes.

Step 2

Toss pita, Halloumi, and remaining 1 Tbsp. oil in reserved bowl. Scatter over vegetables, then turn vegetables over with a large spatula. Roast until squash is fork-tender and cabbage, onion, pita, and Halloumi are browned in spots (cheese should be soft inside), 15–20 minutes. Remove from oven and drizzle with vinegar. Top with sumac and mint.