Wash and dry all produce. Adjust rack to middle position and preheat oven to 425 degrees. Cut sweet potatoes into 1/2-inch cubes. Toss on a baking sheet with a large drizzle of olive oil and a pinch of salt and pepper. Roast in oven until tender and lightly crisped, 20-25 minutes.

Halve, peel, and mince shallots. Strip and chop enough rosemary leaves from stems to give you 2 tsp. Halve lemon.

Heat a large drizzle of olive oil in a large pan over medium-high heat. Pat chicken dry with a paper towel and season all over with salt and pepper. Cook in pan until no longer pink in center, 5-7 minutes per side. Remove from pan and set aside to rest.

Lower heat under pan to medium. Add shallots, chopped rosemary, and a large drizzle of olive oil. Cook, tossing, until softened, 2-3 minutes. Stir in vinegar and fig jam. Simmer until syrupy, about 1 minute. Stir in stock concentrates and 1/3 cup water. Let reduce until thick and saucy, about 3 minutes. (TIP: Add a splash of water if mixture is stiff.) Remove pan from heat. Stir in 2 TBSP butter. Season with salt and pepper.

While sauce simmers, toss lettuce with a big squeeze of lemon and a large drizzle of olive oil in a medium bowl. Season with salt and pepper.

Thinly slice chicken, then divide between plates along with sweet potatoes. Drizzle chicken with sauce. Serve with salad on the side.