For the frittata, heat the olive oil in an ovenproof frying pan and add the spinach, cook until slightly wilted. Pour the beaten egg into the pan along with the olives, chives and red pepper and season, to taste, with salt and freshly ground black pepper.
Continue to cook for 2-3 minutes, or until the egg is almost set, then place under the grill for 2-3 minutes to finish cooking.
For the dressing, place all of the ingredients into a food processor and blend until smooth.
Turn the frittata out onto a serving plate and cut into wedges. Drizzle with some of the dressing.