Squash With Yogurt Sauce and Frizzled Onions

Name: Squash With Yogurt Sauce and Frizzled Onions
Ingredients: 2 medium red onions, thinly sliced; 10 Tbsp. extra-virgin olive oil, divided; Kosher salt; 1 acorn squash, halved, seeded, cut into 1 wedges; 1 delicata squash, cut into 1 rings, seeded; 1 Tbsp. honey; ¾ tsp. Aleppo-style pepper; 1½ cups plain whole-milk Greek yogurt; 1 garlic clove, coarsely chopped; ½ bunch dill, coarsely chopped, plus more for serving; ½ cup Castelvetrano olives, pitted, smashed, plus 1 Tbsp. olive brine; 3 cups cooked brown rice