Authentic Chicken Karahi Curry

Name: Authentic Chicken Karahi Curry
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Cuisine: Asian, Indian
Ingredients: 500 grams Boneless Chicken Breasts; 1 kilo chopped tomatoes (no need to peel); 1 medium red onion finely chopped; 1 teaspoon minced garlic; 1 teaspoon minced ginger; 1 1/2 teaspoon red chili powder; 1 teaspoon garam masala; 1 teaspoon white cumin powder; 1/2 teaspoon turmeric powder; 4 tablespoon vegetable oil; 1/2 cup water; salt to taste; 1 tablespoon chopped coriander; 2 - 3 green chilis (optional); dash of lemon juice