Step 1

Line a rimmed baking sheet with parchment paper and coat evenly with 1 Tbsp. oil. Place rack in middle and top third of oven and set baking sheet on middle rack. Preheat oven to 375°.

Step 2

Whisk egg white, a pinch of salt, and 1 tsp. water in a small bowl until frothy. Pat fish dry inside and out with paper towels. Season fish all over, including cavity, with salt. Stuff cavity with one fourth of scallions, half of sliced garlic, and half of chiles.

Step 3

Place fish on a large plate or another rimmed baking sheet, brush with egg white mixture, and sprinkle with 2 Tbsp. sesame seeds, patting gently to adhere. Turn over and repeat on opposite side, with egg white and another 2 Tbsp. sesame seeds. Transfer fish to preheated baking sheet, drizzle with 1 Tbsp. oil, and season with more salt. Bake until mostly cooked through and the tip of a paring knife easily slides through flesh, 20–25 minutes.

Step 4

Meanwhile, toast remaining 2 tsp. sesame seeds in a small skillet over medium-high heat until golden and fragrant, about 4 minutes. Transfer to a medium bowl and add doenjang, gochujang, honey, and remaining 1 Tbsp. oil. Finely grate in 1 garlic clove and whisk to combine. (This is your ssamjang.)

Step 5

Whisk vinegar and 2 Tbsp. ssamjang in a large bowl. Add radishes and remaining sliced scallions, garlic, and chiles. Toss to combine.

Step 6

Remove fish from oven; heat broiler. Broil fish on top rack until sesame seeds are golden, about 4 minutes. Remove fish from oven and gently turn over by sliding fish to one side of baking sheet and using parchment and a fish spatula to turn it. Season other side of fish with more salt and broil until sesame seeds are golden, about 3 minutes. Transfer fish to a platter and serve with ssamjang, radish salad, kimchi, cooked rice, and lettuce for making wraps.