Adjust rack to top position and preheat oven to 425 degrees. Wash and dry produce.

Trim and halve Brussels sprouts lengthwise. Peel and mince or grate garlic. Zest and quarter lemon.

Toss Brussels sprouts on a baking sheet with a large drizzle of oil, salt, and pepper.

Roast on top rack until browned and tender, 20-25 minutes.

Meanwhile, heat a drizzle of oil in a small pot over medium-high heat. Add couscous, half the garlic, and a big pinch of salt. Cook, stirring constantly, until couscous is toasted and garlic is fragrant, 1-2 minutes.

Add stock concentrate and 1 cup water (2 cups for 4 servings). Bring to a boil, then cover and reduce heat to low. Cook until couscous is tender, 6-8 minutes.

Keep covered until ready to serve.

While couscous cooks, pat salmon* dry with paper towels; season with salt and pepper.

Heat a drizzle of oil in a large, preferably nonstick, pan over medium-high heat. Add salmon to pan, skin sides down. Cook until skin is crisp, 5-7 minutes.

Flip and cook until salmon is cooked through, 1-2 minutes more.

Turn off heat; transfer to a plate. Wipe out pan and let cool slightly.

Dice 2 TBSP butter (4 TBSP for 4 servings) into ½-inch pieces.

In a small bowl, combine mustard, juice from two lemon wedges, 1 TBSP water, ½ tsp sugar, and as much lemon zest as you like. (For 4, use juice from four wedges, 2 TBSP water, and 1 tsp sugar.)

Heat a drizzle of oil in pan used for salmon over medium heat. Add remaining garlic and a pinch of salt. Cook, stirring occasionally, until fragrant, 30-60 seconds.

Whisk in lemon-Dijon mixture. Add diced butter one piece at a time, whisking constantly, until butter has melted and sauce has thickened, 1-2 minutes more.

Keep covered off heat until ready to serve.

Stir ½ TBSP butter (1 TBSP for 4 servings) into pot with couscous until butter melts. Taste and season with salt and pepper if desired.

Divide couscous and Brussels sprouts between plates. Top couscous with salmon; drizzle with lemon-Dijon sauce. Serve with a squeeze of lemon juice and any remaining lemon wedges on the side.