Zucchini Quiche

Bahan-bahan (6 porsi)

• 1 9 -inch refrigerated pie dough
• 1 tablespoon extra-virgin olive oil
• ¼ cup diced red onion
• 1 large garlic clove (minced)
• 2 medium zucchini (about 7 ounces each, cut into 1/8-inch thin slices)
• 1 teaspoon kosher salt
• Freshly ground black pepper
• 6 large eggs
• ½ cup skim milk
• ½ cup part-skim ricotta cheese
• ½ cup part-skim shredded mozzarella cheese
• ¼ cup freshly grated Parmesan cheese
• 2 tablespoons chopped basil (plus more for garnish)