Savory Zucchini Tomato and Basil Pie – TartAmour

Ingredients

• 1 refrigerated pie crust or homemade pie crust
• 2 tablespoons olive oil
• 1 large onion, thinly sliced
• 3 medium zucchinis, thinly sliced
• 3 medium tomatoes, thinly sliced
• 1 cup shredded mozzarella cheese
• 1/2 cup grated Parmesan cheese
• 2 cloves garlic, minced
• 1/4 cup fresh basil leaves, chopped
• 1 teaspoon dried oregano
• Salt and black pepper to taste
• 2 tablespoons Dijon mustard
• 1 egg, beaten