Preheat oven to 400°F (200°C).
In a food processor, combine chickpeas, 1 cup (250 mL) of the spinach, garlic, salt, lemon juice and tahini. Process until fairly smooth, adding 1 to 2 tsp (5 to 10 mL) water, if necessary, to make a spreadable hummus. Season to taste with pepper.
Pat roasted red pepper strips dry. Arrange pita breads on a large baking sheet or 2 sheets, as necessary. Spread with hummus, dividing equally. Arrange strips of roasted red pepper on top; sprinkle evenly with cheese. Bake for about 8 minutes or until pitas are toasted and toppings are hot.
Remove pitas from oven and sprinkle with remaining spinach.