Adjust rack to middle position (middle and top positions for 4 servings) and preheat oven to 425 degrees. Wash and dry produce.

Dice potatoes into ½-inch pieces. Core, deseed, and slice bell pepper into 1-inch-thick strips. Halve, peel, and cut onion into 1-inch-thick wedges. Roughly chop cilantro; reserve 1 tsp (2 tsp for 4 servings) in a small bowl for serving.

Toss potatoes, bell pepper, and onion on a baking sheet with a drizzle of oil, half the curry powder (you'll use the rest in the next step), salt, and pepper. Spread veggies out in a single layer, leaving an empty space in the center (you'll add the chicken later). (For 4 servings, spread veggies out across entire sheet.)

Place 4 TBSP butter (8 TBSP for 4 servings) in a second small microwave-safe bowl; microwave until melted, 30-60 seconds. Stir in remaining curry powder and a pinch of salt. 

Pat chicken* dry with paper towels; season all over with salt and pepper. Place chicken, skin side up, in center of baking sheet with veggies (for 4, add chicken to a second sheet). Pour curry-spiced butter over chicken; rub all over to evenly coat. TIP: Make sure to season the underside of chicken! 

Roast on middle rack until chicken is browned and cooked through and veggies are tender, 40-50 minutes. (For 4, roast chicken on top rack and veggies on middle rack, swapping rack positions halfway through.)

Remove from oven; let chicken rest for at least 5 minutes. TIP: To ensure chicken is cooked through, insert a thermometer into the innermost part of the thigh and breast (avoiding any bones). Once chicken is cooked, the bones may still appear pink—this is OK!

Meanwhile, in a third small bowl, combine yogurt and remaining cilantro. Add water 1 tsp at a time until mixture reaches a drizzling consistency. Season with salt and pepper.

Wrap pitas in damp paper towels; microwave until warm and pliable, 30 seconds.

Slice pitas into quarters. 

Transfer chicken and veggies to a serving plate. Drizzle with yogurt sauce as desired. Sprinkle with reserved cilantro. Serve family style with pita wedges and any remaining yogurt sauce.