Adjust rack to top position and preheat oven to 450 degrees. Wash and dry produce.

Halve potatoes lengthwise. Halve, peel, and thinly slice onion.

Place potatoes in a medium microwave-safe bowl. Cover with plastic wrap; microwave until tender, 6-7 minutes.

In oven-ready tray, toss potatoes and onion with a large drizzle of oil, salt, and pepper. (For 4 servings, evenly divide ingredients between two trays, using a large drizzle of oil in each tray.)

Roast on top rack (be sure your oven has preheated!) for 5 minutes (you’ll add more to the tray then). (For 4, bake two trays side by side on top rack.)

Meanwhile, pat chicken* dry with paper towels.

In a large bowl, combine chicken, yogurt, garam masala, ginger paste, half the garlic powder (you’ll use the rest later), salt, and pepper.

Once potatoes and onion have roasted 5 minutes, carefully remove tray from oven. Transfer chicken and any excess marinade to tray. (For 4 servings, evenly divide chicken and marinade between two trays.) Return to top rack and roast until chicken is cooked through, 18-20 minutes.

Adjust oven to high broil; broil until chicken is lightly browned and charred in spots, 5 minutes more.

When chicken and veggies have 5 minutes remaining, in bowl used for chicken, whisk together half the vinegar, remaining garlic powder, 1 TBSP olive oil, ½ tsp sugar, salt, and pepper (all the vinegar, 2 TBSP olive oil, and 1 tsp sugar for 4 servings).

Add mixed greens; toss to combine.

Once chicken is finished cooking, transfer to a plate.

Stir sour cream into tray with potatoes and onion.

Tear cilantro leaves from stems. 

Divide potatoes and onion and any remaining sauce from tray between shallow bowls. Top with chicken. Garnish with cilantro. Serve salad family style on the side.