Vegetable-Cheese Pie

Ingredients

• olive oil flavored cooking spray
• 6 tablespoons hot water, boiled
• 4 tablespoons nonfat milk
• 2 medium sweet potatoes, peeled and sliced in 1/8-inch rounds
• 12 cup diced onion
• 8 ounces Baby Spinach (about 8 cups)
• 9 ounces black olives, chopped (I use garlic stuffed)
• 2 tablespoons flax seeds, ground
• 1 egg
• 4 egg whites
• 1 cup fat-free ricotta cheese
• 1 sprig fresh basil, chopped
• 3 roma tomatoes, sliced into 1/4-inch rounds
• 2 12 ounces asiago cheese, grated
• 2 12 ounces parmesan cheese, grated
• 1 fresh mozzarella ball, low fat, grated