Moroccan-Spiced Pastitsio With Lamb and Feta

INGREDIENTS

• 2 tablespoons olive oil
• 1 1/4 cups chopped red onions
• 2 large garlic cloves, chopped
• 1 lb ground lamb
• 1 (28 ounce) can diced tomatoes with juice
• 2 tablespoons dried mint
• 1 1/2 tablespoons ras el hanout spice mix
• 1 tablespoon tomato paste
• 3 teaspoons ground cumin, divided
• 1 teaspoon ground cinnamon
• 3 cups whole milk, divided
• 8 tablespoons unsalted butter, divided (1 stick)
• 6 tablespoons all-purpose flour
• 3 large eggs, separated
• 6 ounces feta cheese, crumbled
• 1 lb penne rigate
• 1/2 cup freshly grated parmesan cheese, divided