Mince the garlic and grate the ginger while your grill preheats to 350°F. This allows the grill to reach temperature while you finish prep work. I always mince garlic fresh right before cooking—it releases more aromatic oils than pre-minced garlic, giving the marinade better flavor.

In a small pot over medium heat, combine soy sauce, brown sugar, the minced garlic, grated ginger, and sesame oil. Stir until the sugar dissolves and the mixture becomes fragrant, about 2 minutes. The goal is to marry these flavors together before thickening.

In a small bowl, whisk the cornstarch with 2 tablespoons of water until smooth—this prevents lumps. Pour the cornstarch slurry into the pot while stirring constantly, then simmer for 3-5 minutes until the glaze thickens and becomes glossy. Add the gochugaru to bring in the signature Korean heat and depth. Taste and adjust seasoning as needed. I add the chili flakes toward the end so their flavor stays vibrant rather than mellowing out.

Pat the salmon fillets dry with paper towels—this helps them get a better sear and prevents sticking. Cut them into 2-inch wide portions if not already done. Generously brush both sides of each salmon piece with the glaze from Step 3, reserving about 2 tablespoons for basting during cooking.

Place salmon skin-side down on the preheated 350°F grill. Grill for 5-10 minutes without moving—the skin will crisp and protect the flesh. Using an instant-read thermometer, check that the thickest part reaches 145°F (medium), then carefully flip and cook skin-side up for 1-2 minutes. This short flip time ensures the skin stays crispy while the top caramelizes slightly.

Transfer the salmon to a serving plate immediately. Drizzle with any reserved glaze and sprinkle with toasted sesame seeds for garnish and nutty crunch. Serve hot while the skin is still crispy.