Shrimps in hot coconut sauce

Ingredients

• 1 onion
• 1 ts peanut oil
• 1 ts ginger garlic paste
• 1 ts cumin seed milled
• 1 ts coriander milled
• 1 / 2 ts turmeric
• 1 ts garam masala
• 1 ts cayenne pepper
• 100 g tomatoes strained
• 500 g raw peeled shrimps
• 250 ml coconut milk
• salt
• 2 tbs coriander chopped