Roasted Squash with Lemon-Tahini Sauce

INGREDIENTS

• 4 scallions, cut into 2" pieces
• Aleppo pepper or crushed red pepper flakes
• 1 1/2 teaspoons cumin seeds, divided
• Kosher salt, freshly ground pepper
• 7 tablespoons extra-virgin olive oil, divided
• 1 1-pound delicata squash, scrubbed, cut into 1"-thick wedges or rings, seeded
• 2 tablespoons fresh lemon juice
• 1 small kabocha squash or large acorn squash (1 pound), scrubbed,
• 1 tablespoon tahini (sesame seed paste)