Greek Stuffed Shells Recipe

Ingredients

• 1 pound ground lamb
• 3 teaspoons kosher salt, divided
• 1 tablespoon olive oil
• 3 cups chopped red onion, divided
• 1 (28-ounce) can crushed tomatoes
• 5 teaspoons chopped fresh oregano, divided
• 2 cups crumbled feta cheese, divided
• 1 (15-ounce) container whole-milk ricotta cheese
• 1 large egg
• 16 jumbo pasta shells, cooked al dente according to package directions
• Fresh oregano leaves, ground black pepper, lemon zest