Heat oil in a skillet over medium heat. Add onion and zucchini, and cook until softened, about six minutes. Preheat oven to 400F.
Place pitas on a baking sheet. Spread an equal amount of the refried beans over pitas and top with arugula, mozzarella cheese, cooked zucchini and onion, and tomatoes. Form a well in the centre of the toppings of each pizza and crack an egg into each, being careful not to break yolks.
Cook in oven about 15 to 25 minutes, until eggs are set as firmly as desired. Garnish with additional arugula and black pepper.
Per pizza: 437 calories, 26 g protein, 15 g fat (6 g saturated fat), 55 carbohydrates, 9 g fibre, 233 mg cholesterol, 707 mg sodium.