Season the chicken generously with salt and pepper. In a large saucepan or Dutch oven, heat oil over medium-high heat. Place chicken in pot, skin side down and cook until browned and crisp, 5-6 minutes per side. Remove chicken from the pot and transfer to a plate.
Add the onion and sauté until softened, about 5 minutes. Add ginger, paprika and coriander and cook, stirring often, for another 2 minutes. Arrange chicken pieces evenly over onion mixture. Add 2 1/2 cups water and bring to a boil. Reduce to a simmer, cover and cook until chicken is tender and cooked through, 40-45 minutes.
Transfer chicken to a rimmed serving platter and increase heat to high. Boil cooking liquid until reduced by half, 12-15 minutes. Stir in cilantro and dates and season with salt and pepper. Pour sauce over the chicken. Serve with lemon halves.