Chicken Boti Kebabs (Murgh Boti)/Madhur Jaffrey

1-1/2 pounds boned and skinned chicken breasts, cut into 1-inch cubes
1 teaspoon salt
2 tablespoons lemon juice
1 tablespoon peeled and very finely grated fresh ginger
2 cloves garlic, crushed to a pulp
1 teaspoon ground cumin
1 teaspoon bright red paprika
3/4 teaspoon cayenne pepper
6 tablespoons tomato ketchup
Freshly ground pepper
1/4 teaspoon ground turmeric
3 tablespoons corn or peanut oil

Put chicken in a bowl. Add salt and lemon juice and rub them in. Prod chicken pieces lightly with tip of a knife and rub seasonings in again. Set aside for 20 minutes. Then add ginger, garlic, cumin, paprika, cayenne, ketchup, lots of black pepper, and the turmeric. Mix well, cover, and refrigerate for 6 to 8 hours. (Longer will not hurt.)
Just before serving, preheat broiler. Thread meat onto two to four skewers (the flat, swordlike ones are best.) Brush with oil and balance the skewers on the rim of a shallow baking tray. Place about 5 inches from the source of the heat and broil for 6 minutes on each side, or until lightly browned and cook through.
Note: I often cook these without the skewers, just turning the chicken pieces once or twice while they are broiling.
Serves 4 as a main course, 8 as an appetizer