Quick yellow curry with green peppers and sweet potatoes

– 2 green peppers
– 2 onions
– 1 clove of garlic
– 3 sweet potatoes, peeled and chopped
– 2 tbsp yellow curry paste
– 1 tin of coconut milk
– 4 chicken thigh fillets, chopped
– 1 tbsp coconut oil
– Salt
Optional: coriander