Moussaka with Yogurt Béchamel

Name: Moussaka with Yogurt Béchamel
Ingredients: 2 tablespoons unsalted butter; 1/3 cup all-purpose flour; 1 1/2 cups heavy cream; 1 1/2 cups whole milk; 2 1/2 large onions, 2 diced; 1 bay leaf; 2 whole cloves; 1/2 cup plain whole milk yogurt; Freshly grated nutmeg; Salt and freshly ground pepper; 1/4 cup dried currants; 6 tablespoons extra-virgin olive oil, plus more for brushing; 1 pound ground beef; 1 pound ground lamb; 3 1/2 tablespoons ras el hanout (see Note); 2 tablespoons plus 1/2 teaspoon cinnamon; 1 teaspoon crushed red pepper; 6 garlic cloves, thinly sliced; 2 cups dry red wine; One 28-ounce can whole tomatoes, chopped, juices reserved; 2 medium eggplants peeled and sliced lengthwise 1/2 inch thick; 2 green bell peppers, diced; 2 cups grated Parmesan cheese