Simple throw-together recipe, for which you really must have garden-fresh flat-leafed parsley. Use lime juice if possible, it's so tangy. Parsley is one of the most nutritious herbs, packed with antioxidants, but seldom used in quantity. I can eat this by the spoonful! This is a mild-tasting thick sauce, which improves in flavour if left at room temperature for a few hours. You might need less olive oil. Please taste the sauce and season to your taste. I find that despite the olives and capers it needs a good pinch of sea salt flakes. This pesto or puree will not overpower delicate tastes like fish. It's great with chicken, roast veggies, potatoes, or spread it thickly on toast and top with poached egg.