Creamy Ricotta Beef Stuffed Shells (Cozy Baked Pasta Dinner)

Ingredients

• 24 jumbo pasta shells, plus a few extra in case some tear
• 1 tablespoon kosher salt, for the pasta water
• 1 tablespoon olive oil
• 1 lb (450 g) lean ground beef
• 1 small yellow onion, finely diced
• 3 cloves garlic, minced
• 1 teaspoon Italian seasoning
• 1/2 teaspoon kosher salt
• 1/4 teaspoon black pepper
• 15 oz (425 g) whole-milk ricotta cheese, drained if watery
• 1 large egg
• 1 cup (115 g) shredded low-moisture mozzarella, divided
• 1/2 cup (50 g) grated parmesan cheese
• 2 tablespoons chopped fresh parsley or basil
• 3 cups (720 ml) marinara sauce
• 1 tablespoon chopped fresh parsley or basil, for serving