Preheat oven to 425 degrees. Wash and dry all produce. Trim and halve zucchini lengthwise, then slice into thin half-moons. Zest and quarter lemon. In a small bowl, combine brown sugar, stock concentrate, mustard, and 2 TBSP water (3 TBSP for 4 servings). Set aside.

Melt half the garlic herb butter (you’ll use the rest later) in a small pot over medium-high heat. Add couscous and as much lemon zest as you like. Cook, stirring, until couscous is lightly toasted, about 1 minute. Stir in 3/4 cup water (11/2 cups for 4 servings) and a large pinch of salt. Bring to a boil, then cover, remove from heat, and set aside.

Toss zucchini on a baking sheet with a drizzle of oil and a large pinch of salt and pepper. Roast on top rack, flipping halfway through, until browned and tender, 15-20 minutes.

Meanwhile, pat pork dry with paper towels; prick all over with a fork or knife. Season all over with salt and pepper. Heat a drizzle of oil in a large pan over medium-high heat. Add pork and cook until browned and cooked through, 4-6 minutes per side. Remove from pan and set aside.

Add brown sugar mixture to same pan over medium heat. Bring to a simmer and cook until slightly thickened, 1-2 minutes. Reduce heat to low and stir in 1 TBSP plain butter (2 TBSP for 4 servings) until melted. Add pork and turn to coat in glaze. Turn off heat.

Fluff couscous with a fork; stir in remaining garlic herb butter and a large squeeze of lemon juice. Season generously with salt and pepper. Divide couscous between plates and top with pork. Serve zucchini to the side. Drizzle pork with remaining glaze. Serve with remaining lemon wedges on the side.