Step 1

Position a rack in upper third of oven; preheat broiler to high. Line a baking sheet with foil and coat with cooking spray.

Step 2

Whisk gochujang, mirin, 1 tablespoon tamari, honey, 1/2 teaspoon sesame oil, 1/4 of the garlic and ginger in a small bowl. Pat salmon dry and place skin-side down on the prepared pan. Brush the salmon with the glaze. Broil until the salmon is just cooked through, 5 to 8 minutes, depending on thickness.

Step 3

Meanwhile, heat the remaining 1 teaspoon sesame oil in a large skillet over medium-low heat. Add the remaining 3 cloves garlic and cook, stirring, until fragrant and just starting to brown, about 3 minutes. Add spinach and cook, stirring, until wilted and the pan is dry, about 3 minutes. Remove from heat and stir in the remaining 1 tablespoon tamari.

Step 4

Serve the salmon over the spinach.