Place the coriander, garlic, cashew nuts and parmesan in the bowl of a food processor and process until finely chopped. Keeping the food processor running, gradually add the oil in a thin, steady stream until well combined and a smooth paste forms. Season to taste with salt and pepper. Store in an air tight container pour in extra oil to cover the surface of the pesto (this will prevent the coriander from oxidising and turning black).
Serve with grilled fish, chicken and pasta dishes.