Butter-Basted Chicken Breasts

Dice sweet potatoes into ½-inch pieces. Place in a large pot with enough salted water to cover by 2 inches. Boil until tender, 15-20 minutes. Reserve ½ cup potato cooking liquid, then drain. Melt 1 TBSP plain butter in same pot over medium heat. Add scallion whites; cook until softened, 1-2 minutes. Add drained sweet potatoes; mash until smooth. Season with salt and pepper. Keep covered off heat until ready to serve.

Meanwhile, carefully toss Brussels sprouts on one side of prepared sheet with a drizzle of oil, salt, and pepper; arrange cut sides down. Add bacon to empty side; sprinkle with salt and pepper. (For 4, use 2 sheets; roast Brussels sprouts on top rack and bacon on middle.) Roast 10 minutes, then remove from oven; sprinkle bacon with brown sugar. Return to oven until bacon is crispy and Brussels sprouts are tender, 10-15 minutes more.

Meanwhile, pat chicken dry with paper towels; season all over with salt and pepper. Heat a large drizzle of oil in a large pan over medium-high heat. Add chicken and cook until browned and cooked through, 5-7 minutes per side. During last 2 minutes of cooking, reduce heat to low and add garlic herb butter. Spoon over chicken to coat. Turn off heat. Leaving butter in pan, transfer chicken to a plate.

Add minced shallot to pan with reserved garlic herb butter. Cook over low heat until softened, 1-2 minutes. Stir in demi-glace and ¼ cup water. Simmer until slightly thickened, 1-2 minutes. Turn off heat. Stir in 2 packets sour cream (4 for 4 servings) and any resting juices from chicken. Season with salt and pepper.