Tomato Sausage Tart

Ingredients

• 1 (9 inch) refrigerated pie crust
• ½ pound bulk Italian sausage
• 1 cup chopped onion
• 1 clove garlic, minced
• 2 tablespoons Dijon mustard
• 1 egg
• ½ cup light cream
• salt and pepper to taste
• 2 cups shredded mozzarella cheese, divided
• 2 pounds tomatoes, sliced
• 1 teaspoon dried oregano, or to taste
• 1 teaspoon dried basil, or to taste
• 2 cups chopped fresh basil
• 1 tablespoon lemon juice
• 1 cup vegetable oil
• salt to taste