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

Dice potatoes into ½-inch pieces. (TIP: For a smoother texture, peel potatoes first.) Cut broccoli into bite-size pieces if necessary. Trim and thinly slice scallions, separating whites from greens.

Add potatoes to a medium pot with enough salted water to cover by 2 inches. Bring to a boil and cook until tender, 10-12 minutes. Reserve ½ cup potato cooking liquid, then drain.

Return potatoes to pot. Mash with sour cream and 1 TBSP butter (2 TBSP for 4 servings) until smooth, adding splashes of reserved potato cooking liquid as needed. Season generously with salt and pepper.

Keep covered off heat until ready to serve.

While potatoes cook, toss broccoli on a baking sheet with a drizzle of oil, salt, and pepper. Roast on middle rack until browned and tender, 15-20 minutes. TIP: Tent with foil to keep warm until ready to serve.

Meanwhile, pat chicken* dry with paper towels. Place between two large pieces of plastic wrap; pound with a mallet or heavy-bottomed pan until about ½ inch thick. Season all over with salt and pepper.

Sprinkle chicken all over with half the flour, pressing to adhere; shake off any excess.

Heat a large drizzle of oil in a large pan over medium-high heat. Add coated chicken; cook until browned and cooked through, 4-6 minutes per side. (For 4 servings, you may need to cook in batches.)

Turn off heat; transfer to a plate. Wipe out pan.

Add bacon in a single layer to pan used for chicken; heat over medium-high heat. Cook, turning occasionally, until crispy, 4-6 minutes. Turn off heat; transfer to a paper-towel-lined plate. Discard any burnt bits and all but 1 TBSP bacon fat (2 TBSP for 4 servings) from pan. TIP: Not enough bacon fat in the pan? Add a little butter!

Add scallion whites to pan with reserved bacon fat. Cook over medium-low heat, stirring constantly, until softened and fragrant, 30-60 seconds.

Sprinkle remaining flour into pan; stir to combine. Slowly whisk in ¾ cup water (1½ cups for 4) and stock concentrate. Bring to a simmer; cook, whisking constantly, until thickened, 1-2 minutes. Stir in crème fraîche; season with salt and pepper if desired.

Stir in crème fraîche; season with salt and pepper if desired.

Once bacon is cool enough to handle, finely chop.

Stir half the chopped bacon into pan with gravy. Transfer chicken to pan; turn to coat.

Divide mashed potatoes, chicken, and broccoli between plates in separate sections. Top chicken and potatoes with remaining bacon gravy. Garnish with scallion greens and remaining chopped bacon. Serve.