Step 1

Preheat broiler with rack 8 inches from heating element. Combine leeks, potatoes, broth, and 2 tablespoons oil in a large ovenproof skillet. Season with salt and pepper. Broil, stirring once halfway through, until potatoes are crisp-tender, 8 to 10 minutes.

Step 2

Meanwhile, rub chicken with remaining 1 tablespoon oil. Season with coriander, salt, and pepper, then place, skin-side down, atop leeks and potatoes. Broil 8 minutes. Flip chicken; scatter lemon wedges around it. Broil until a thermometer inserted into thickest parts of thighs (avoiding bones) registers 165 degrees, 10 to 12 minutes more. Transfer chicken to serving plates. Stir spinach into leek-potato mixture until wilted. Serve chicken with vegetables, lemon wedges, and pan juices.