• Adjust rack to top position (top and middle positions for 4 servings) and preheat oven to 450 degrees. Wash and dry produce. • Cut potatoes into ½-inch-thick wedges. Trim and halve zucchini lengthwise; cut crosswise into ½-inch-thick half-moons. Zest and quarter lemon. Mince chives.

• Toss potatoes on one side of a baking sheet with a large drizzle of olive oil, salt, and pepper. (For 4 servings, spread potatoes out across entire sheet.) • Roast on top rack for 10 minutes (you’ll add the zucchini then).

• Meanwhile, in a large bowl, toss zucchini with a drizzle of olive oil and a pinch of salt and pepper. • Once potatoes have roasted 10 minutes, remove sheet from oven; add zucchini to empty side. (For 4 servings, leave potatoes roasting and add zucchini to a second sheet; roast on middle rack.) • Return to top rack until potatoes are golden brown and zucchini is lightly browned, 12-15 minutes more. Carefully toss zucchini with lemon zest.

• While potatoes and zucchini roast, pat salmon* dry with paper towels; season all over with salt and pepper. • Heat 1 TBSP butter and 1 TBSP olive oil in a large pan over medium-high heat. Add salmon, skin sides down, and cook until skin is crisp and fish is almost cooked through, 5-7 minutes. Flip and cook until cooked through, 1-2 minutes more. • Turn off heat; remove from pan and set aside. Wipe out pan.

• Return same pan to medium-high heat. Add stock concentrate, half the mustard (all for 4 servings), juice from half the lemon, and ¼ cup water (1⁄3 cup for 4). Simmer until slightly thickened, 2-3 minutes. Turn off heat. • Stir in sour cream, half the chives, and 1 TBSP butter (2 TBSP for 4) until combined. (TIP: If sauce seems too thick, add more water 1 tsp at a time until it reaches a drizzling consistency.) Season with salt and pepper.

• Divide salmon, potatoes, and zucchini between plates. Drizzle sauce over salmon. Garnish with remaining chives if desired. Serve with remaining lemon wedges on the side.