Step 1

Preheat the oven to 325°F

Step 2

Cut the salmon into four portions and set aside.

Step 3

In a large oven-safe pan that can hold all of the salmon pieces plus some, add the butter. Put the pan on medium heat and melt the butter, stirring occasionally, until it starts to fizz slightly and brown.

Step 4

Once the butter reaches a golden brown, turn off the heat and add in the onions. Stir to coat the onions in the brown butter. You want them to soften slightly in the heat of the pan, but they don't need to cook all the way, the oven will take care of that later.

Step 5

In a small bowl, whisk together the brown sugar, soy sauce, gochujang and vinegar. Pour this into the pan and mix to create a thick and rich sauce.

Step 6

Create some space in the pan for the salmon, moving the onions and sauce to the sides. Place the salmon skin-side-down on the pan. Spoon the onions and sauce over each piece of salmon until they are well coated.

Step 7

Slow-roast the salmon in the oven for 15-16 minutes at 325°F.

Step 8

Remove from the oven, spoon more of the warm sauce over the salmon (you'll have plenty left over, save for drizzling over the rest of your meal, and for rice and vegetables throughout the week!) and flake the salmon away from the skin.

Step 9

Serve the salmon on a large plate, scatter with herbs and spoon more sauce over as desired. Finish with a squeeze of lemon and enjoy!