Fish Suruwa (Fijian Fish Curry)

Name: Fish Suruwa (Fijian Fish Curry)
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Cuisine: Indian, Asian
Ingredients: 3 tablespoons (44 milliliters) vegetable oil; 1 medium onion (peeled and diced); 1 cinnamon stick; 3 cloves garlic (peeled and minced); 2 long red chilies (stems and seeds removed, chopped); 1 1/2 teaspoons garam masala; 1 teaspoon ground toasted cumin; 1 teaspoon ground turmeric; 2 medium tomatoes (finely diced); 1 1/2 pounds (680 grams) firm white fish; Juice of 1 lemon; 1 2/3 cups (400 ml) coconut milk; Salt (to taste); Freshly chopped cilantro (for garnish); Steamed white rice (for serving)