Heat 1 tbsp olive oil in a large pan and add 2 finely sliced onions. Cook until softened, about 10 mins.
Add 2 crushed garlic cloves, 1 tsp garam masala, 1 tsp turmeric and 1 tsp ground coriander, then stir to combine. Cook for 1-2 mins, then pour in a 400g can of plum tomatoes, break up with a wooden spoon and simmer for 10 mins.
Pour in a 400ml can of coconut milk and season. Bring to the boil and simmer for a further 10-15 mins until the sauce has thickened.
Tip in a drained and rinsed 400g can of chickpeas and 2 quartered large tomatoes, and warm through. Scatter over roughly chopped coriander from ½ small pack and serve with fluffy rice.