Heat 3 tablespoons of oil in a casserole. Sauté onions until transparent, 2-3 minutes, then add garlic and sauté until fragrant, 1-2 minutes. Stir-fry the chicken pieces until evenly browned. Pour in crushed tomatoes and water. Add the bay leaf and bring to a boil, then simmer until chicken is just tender, about 20 minutes.