Preheat the oven to 400 degrees F. Place the salmon on a baking sheet.: Warm air in the oven helps set the glaze and cook the thick fillets evenly, you will notice the kitchen aroma shift as the oven comes up to temperature. Ensure the salmon is placed skin side down if it has skin, or on parchment if you prefer an easy cleanup. A common mistake is crowding the pan, which traps steam and prevents crisping, so leave space between fillets for air circulation.
In a small bowl, whisk together the sugar, garlic powder, paprika, salt, pepper and cumin. Sprinkle it all over the salmon filets. Drizzle each filet with the maple syrup and use a spoon to kind of “spread” it all over the filet.: As the spice blend meets the sticky maple syrup , you should see a glossy coating that clings to the salmon , this is the foundation of the caramelized crust. Work gently so you do not press the flesh too much, which can compact the flakes. If the rub is uneven you may end up with some spots caramelized and others bland, so aim for an even layer.
Roast for 10 to 15 minutes, until the salmon just flakes with a fork. If desired, you can brush with a little more maple syrup when it comes out of the oven. Top with chopped chives. Serve immediately with brown butter couscous!: While roasting you will hear a quiet sizzle and smell sweet, toasty notes from the sugar breaking down. Watch for the center to go from translucent to opaque and test by gently flaking with a fork, the fish should separate into moist flakes. Overcooking dries the salmon , so pull it at the first sign of flaking. Brushing extra syrup after roasting enhances gloss but add sparingly so it does not pool.
brown butter couscous: Toasting the couscous in butter creates warm, nutty aromas as the edges take on a golden tint. You will notice tiny pops as the grains heat and release a toasted scent. This step adds complexity that boiling alone cannot achieve. Rushing the toast can leave the couscous bland, so stir gently until you see light browning.
Heat a large saucepan over medium heat and add the butter. Stir in the couscous until coated, then cook for 2 to 3 minutes, stirring, until the couscous is slightly toasty. Add in the stock and salt and bring the mixture to a boil. Once boiling, reduce to a simmer and cover. Cook for 15 minutes, or until the liquid is absorbed.: When the stock hits the pan the steam will carry toasty butter aromas, and you should see the liquid swell the pearls. Reducing to a gentle simmer prevents the grains from breaking apart, delivering individual, tender pearls. A common error is lifting the lid too often, which releases steam and extends cooking time, so resist peeking until the liquid is absorbed.
While the couscous is cooking, heat a small saucepan over medium heat and add the butter. Cook, whisking often, until brown bits appear on the bottom of the pan. Remove the butter from the heat and stir in the garlic cloves.: As the butter turns from pale yellow to amber you will smell a deep roasted, nutty perfume, and small brown speckles will form. Once the butter reaches that point, get it off the heat right away, because browned butter can quickly go from fragrant to burned. When you stir in the minced garlic , the steam will wake up bright aromatics, so timing matters to avoid raw garlic sharpness.
Once the couscous is finished, drizzle with the garlic brown butter. Toss and serve.: The final toss should coat each pearl with glossy, savory fat, releasing waves of warm butter and sweet garlic scent. Use a fork to gently fluff, and you will see how the butter clings to the couscous, providing sheen and silkiness. Avoid overmixing, which can crush the pearls and make the texture mushy. Serve right away so the couscous retains its tender bite and the salmon stays hot.