How to Make It
Position one oven rack 3 inches from heat; position second rack in middle of oven. Preheat oven to 350°F. Line a rimmed baking sheet with parchment paper.
Stir together white sesame seeds, black sesame seeds, pepitas, sunflower seed kernels, brown sugar, 3/4 teaspoon chile-sesame oil, orange zest, and 1/4 teaspoon kosher salt in a small bowl. Gradually drizzle in 1 tablespoon honey, stirring to combine. Transfer to prepared baking sheet; press mixture into an 8-inch square.
Bake on middle rack in preheated oven until sugar melts, 8 to 10 minutes. Let cool on baking sheet 25 minutes (brittle will harden as it cools). Break into bite-size pieces.
Stir together lime juice, 1 tablespoon chile-sesame oil, remaining 2 teaspoons honey, and remaining 1/4 teaspoon kosher salt in a small bowl; set aside.
Increase oven temperature to high broil. Gently toss together citrus and remaining 1 tablespoon chile-sesame oil in a large bowl. Arrange citrus in an even layer on a wire rack set inside a rimmed baking sheet. Broil on top rack in preheated oven until sizzling, 1 minute and 30 seconds to 2 minutes.
Transfer roasted citrus to a large platter. Drizzle evenly with lime juice mixture; garnish with sea salt, and top with brittle.