Wash and dry all produce. Trim and thinly slice scallions, separating whites from greens. Pick rosemary leaves from stems; finely chop leaves until you have 1 tsp (2 tsp for 4 servings). Halve, core, and dice apple.

Heat a drizzle of olive oil in a small pot over medium-high heat. Add scallion whites and half the chopped rosemary. Cook until fragrant, 30 seconds to 1 minute. Pour in 3/4 cup water (11/4 cups for 4 servings). Bring to a boil and immediately stir in couscous and a big pinch of salt and pepper. Turn off heat, cover, and let stand until tender, 8-10 minutes.

Meanwhile, pat pork dry with paper towels; season all over with salt and pepper. Melt 1 TBSP butter (2 TBSP for 4 servings) in a large pan over high heat. Add pork and cook until browned and cooked through, 2-3 minutes per side. (For 4, you may need to cook in batches.) Transfer to a plate.

Heat same pan over medium heat. Add remaining chopped rosemary, 1 TBSP vinegar (2 TBSP for 4 servings; we’ll use more later), maple syrup, stock concentrate, and 1/4 cup water (1/3 cup for 4). Simmer until slightly thickened, 1-2 minutes. Stir in 1 TBSP butter, then season with salt and pepper. Return pork to pan; turn to coat in sauce. Turn off heat.

In a medium bowl, whisk together mayonnaise and remaining vinegar. Add mixed greens and apple; toss to combine. Season with salt and pepper.

Fluff couscous with a fork and divide between plates. Top with pork. Drizzle with any remaining sauce and garnish with scallion greens. Serve with salad on the side.