Heat the butter / ghee over high heat in a large pan and add the chopped onion. Cook until just starting to brown and then reduce heat to medium / medium-low and add the sundried tomato and chives and cook for a further 2-3 minutes.
Reduce to low heat and stir in the coriander, oregano and chilli powder. Cook for a further 2-3 minutes whilst stirring constantly.
Add the chopped tomatoes and basil and simmer for around 10 minutes or until sauce is slightly reduced.
Stir in the sour cream and parmesan and season well. Retain over low heat for around 10 minutes. In the meantime, cook pasta according the packet directions.
Drain pasta (if required) and mix well with sauce. Serve immediately either on its own or with garlic bread to accompany.