Heat 2 Tbsp oil in a nonstick pan over medium heat. Add 2 cups cooked rice and drizzle over oil from tin of smoked salmon. Press the rice in an even layer for maximum surface area. Cook undisturbed until rice begins to brown at edges, 5-7 minutes. Flip and cook for 2-3 more minutes until crispy on both sides.
Make the sauce by whisking together 2 Tbsp sesame paste, 2 Tbsp orange juice, 1/2 Tbsp rice vinegar, and season with kosher salt to taste.
Add half of the crispy rice to eat plate. Top with large flakes of the tinned smoked salmon, watermelon radish, and mandarin orange. Drizzle the sauce over each plate and garnish with cilantro leaves and sesame seeds.
