Preheat oven to 425F. Cut four slits into the belly of the fish. Season the fish with salt, pepper, and paprika, then drizzle with olive oil. Place lemon slices and onion slices under and around the fish. Stuff the fish cavity with sliced garlic, sliced ginger, cilantro, and lemon slices. Roast in the oven for 35 minutes. Meanwhile, combine all sauce ingredients: soy sauce, oil, Mirin, juice from 1/2 squeezed lemon, gochugaru (or chili flakes), minced garlic, minced ginger, thinly sliced green onions, and finely chopped cilantro. At the 35-minute mark, brush the prepared sauce over the fish. Broil the fish for 5-8 minutes until the skin is crispy. Enjoy.
