Warm Winter Vegetable Salad With Halloumi

Name: Warm Winter Vegetable Salad With Halloumi
Ingredients: 5 Tbsp. extra-virgin olive oil, divided; 2 garlic cloves, finely chopped; 1½ tsp. kosher salt; 1 tsp. Aleppo-style pepper; ½ small head of red cabbage (about 10 oz.), cut into 1 pieces; 1 medium red onion, cut into 8 wedges through root end; 1½ lb. winter squash, preferably delicata, halved, seeds removed, sliced crosswise ½ thick; 1 large pita bread, split into 2 layers, cut or torn into 1½–2 pieces; 8 oz. Halloumi cheese, cut into 1 pieces; 2 Tbsp. apple cider vinegar; 1½ tsp. ground sumac; Mint springs (for serving)