Moroccan-Spiced Pastitsio with Lamb and Feta

Ingredients

• 6 tablespoons flour 
• 28 ounce frangelico diced canned
• 2 tablespoons mint dried
• 3 large eggs separated
• 6 ounces feta cheese crumbled
• 2 large garlic clove chopped
• 1 teaspoon ground cinnamon 
• 3 teaspoons ground cumin divided
• 1 pound lamb 
• 2 tablespoons olive oil 
• 0.5 cup parmesan cheese divided freshly grated
• 1 pound penne pasta 
• 1.5 tablespoons ras el hanout spice mix 
• 1.3 cups onion red chopped
• 1 tablespoon tomato paste 
• 8 tablespoons butter unsalted divided (1 stick)
• 3 cups milk whole divided

Equipment

• bowl
• frying pan
• baking sheet
• sauce pan
• oven
• whisk
• pot
• baking pan
• potato masher

Directions

1. Heat oil in large skillet over medium-high heat.
2. Add onion and garlic; sauté until onion softens, about 5 minutes.
3. Add lamb; cook until brown, breaking into small pieces, about 8 minutes. Stir in tomatoes with juice, mint, ras-el-hanout, tomato paste, 2 1/2 teaspoons cumin, and cinnamon. Bring to boil. Reduce heat to medium-low. Simmer until lamb mixture is thick, stirring often, 15 to 18 minutes. Season with salt and pepper.
4. Meanwhile, bring 2 cups milk to simmer in medium saucepan.
5. Remove from heat; cover to keep warm. Melt 6 tablespoons butter in heavy large saucepan over medium heat.
6. Add flour; whisk until smooth. Reduce heat to medium-low; cook until roux is pale golden, whisking often, 3 to 4 minutes. Gradually add warm milk to roux, whisking until sauce is smooth.
7. Whisk 1 cup milk and 3 egg yolks in medium bowl; whisk into sauce.
8. Whisk in feta and 1/2 teaspoon cumin. Bring sauce to boil, whisking often. Reduce heat to medium-low; simmer until slightly thickened, mashing with potato masher to break up cheese, about 5 minutes. Season sauce with salt and pepper. DO AHEAD: Can be made 1 day ahead. Cover; chill. Rewarm over low heat, whisking often, before using.
9. Preheat oven to 400°F. Butter deep 14-cup baking dish. Cook pasta in large pot of boiling salted water until tender but still firm to bite, stirring occasionally.
10. Drain pasta; return to same pot.
11. Mix 2 tablespoons butter into pasta.
12. Add egg whites and 1/4 cup Parmesan; stir to blend.
13. Spread 4 cups pasta in dish.
14. Spread lamb mixture over. Top with remaining pasta. Spoon sauce over; sprinkle with 1/4 cup Parmesan.
15. Place dish on rimmed baking sheet.
16. Bake pastitsio until heated through, about 40 minutes.
17. Let stand 5 to 10 minutes.