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

Trim green beans if necessary. Toss on a baking sheet with a drizzle of oil, salt, and pepper.

Roast on top rack until browned and tender, 12-15 minutes.

Meanwhile, strip rosemary leaves from stems; finely chop leaves until you have 1 tsp (2 tsp for 4 servings).

Pat pork* dry with paper towels and season all over with salt and pepper.

Heat a drizzle of oil in a large pan over medium-high heat. Add pork; cook until browned and cooked through, 4-6 minutes per side.

Turn off heat; transfer pork to a cutting board. Wipe out pan.

Swap in chicken* for pork; cook until browned and cooked through, 3-5 minutes per side.

Heat a drizzle of oil in same pan over medium-high heat. Add chopped rosemary; cook, stirring, until fragrant, 30 seconds.

Stir in stock concentrate, vinegar, ¼ cup water (⅓ cup for 4 servings), and 2 tsp sugar (4 tsp for 4). Bring to a simmer and cook, stirring occasionally, until slightly reduced, 3-4 minutes. Season generously with pepper.

Turn off heat. Stir in half the garlic herb butter until melted (you’ll use the rest in the next step).

Halve baguette lengthwise and toast; spread cut sides with remaining garlic herb butter. Season with salt and pepper. Halve on a diagonal.

Thinly slice pork crosswise.

Divide pork, garlic bread, and green beans between plates. Top pork with balsamic rosemary pan sauce and serve.

Thinly slice chicken crosswise.