Step 1

Pat duck dry with paper towels; season all over with salt and pepper. Place skin sides down in a large pan. Cook over medium heat until skin is crisp and most of the fat has rendered, 15-20 minutes, pouring off fat as it renders. (TIP: Lower heat if skin begins to brown too quickly.) Flip and cook to desired doneness, 3-5 minutes more. Turn off heat; transfer to a cutting board to rest. Wipe out pan.

Step 2

Meanwhile, wash and dry all produce. Peel, then dice potatoes into ½-inch pieces. Place in a medium pot with enough salted water to cover by 2 inches. Bring to a boil and cook until very tender, 15-20 minutes. Drain.

Step 3

Strip 1 tsp thyme leaves (2 tsp for 4 servings) from stems; discard stems. Mince garlic. Halve tomatoes and lemon. Halve, peel, and mince shallot until you have ¼ cup (½ cup for 4; use any remaining shallot as you like).

Step 4

Melt 2 TBSP butter (4 TBSP for 4 servings) in pot used for potatoes over medium heat. Add garlic and cook, stirring, until fragrant, 20-30 seconds. Add potatoes, ⅓ cup milk (⅔ cup for 4), salt, and pepper. Mash until smooth and creamy. (TIP: If needed, add more milk a splash at a time.) Cover pot to keep warm.

Step 5

Heat a drizzle of oil in pan used for duck over medium heat. Add minced shallot and thyme. Cook until shallot is softened, 2-3 minutes. Add demiglace, jam, and ¼ cup water (⅓ cup for 4 servings), stirring to break up jam. Let simmer until thick and glossy, 2-3 minutes. Stir in a squeeze of lemon juice. Season with pepper and more lemon juice to taste.

Step 6

In a medium bowl, combine watercress, tomatoes, a squeeze of lemon juice, and a large drizzle of olive oil; toss to thoroughly coat. Season with salt and pepper. Thinly slice duck crosswise. Divide potatoes and duck between plates. Drizzle duck with sauce. Serve with salad on the side.