Indian Prawn Curry (Spiced Prawn Stew)

Ingredients

• 500 g fresh prawns (cleaned and deveined)
• 2 tbsp vegetable oil
• 1 large onion (finely chopped)
• 2 tomatoes (pureed)
• 3 cloves garlic (minced)
• 1 inch ginger (minced)
• 2 green chilies (slit lengthwise)
• 1 tsp ground turmeric
• 1 tsp ground coriander
• 1/2 tsp ground cumin
• 1/2 tsp red chili powder (adjust to taste)
• 1/2 tsp garam masala
• 1/2 tsp mustard seeds
• 1/2 tsp fenugreek seeds (optional)
• 1 cup coconut milk
• 1/2 cup water
• Fresh cilantro leaves (chopped for garnish)
• Salt (to taste)
• Juice of 1 lemon