Stuffed Shells

Bahan-bahan (6 porsi)

• 20 jumbo pasta shells (cooked to package instructions)
• 1/2 medium onion (chopped)
• 3 g arlic cloves (minced)
• 1 tsp salt (divided)
• 1/2 tsp freshly ground black pepper (divided)
• 1/4 tsp dried oregano
• 3 cups marinara sauce
• 15 oz ricotta cheese*
• 1 large egg
• 1/3 cup parmesan cheese
• 3 cups shredded mozzarella cheese (divided)
• 1/4 cup parsley (plus more to garnish)