Sausage-Fennel Lasagna Rolls | TASTE

Ingredients

• 2 tbsp extra-virgin olive oil
• 1 lb sweet Italian fennel sausage, casings removed
• 1 ½ tsp finely grated lemon zest
• ½ tsp finely chopped fresh rosemary
• 1 lg fennel bulb (1 ½ pounds), cut into ½-inch pieces
• 1 md yellow onion, cut into ½-inch pieces
• ½ tsp coarse kosher salt (preferably Diamond Crystal)
• ½ tsp freshly ground black pepper
• ½ c freshly grated Parmesan cheese
• 1 lb Fontina cheese, shredded (about 4 cups)
• 4 c Classic Béchamel, warm
• 15 dry lasagna noodles, cooked and cooled
• 4 tbsp (1/2 stick) unsalted butter
• ¼ c all-purpose flour
• 4 c (1 quart) whole milk
• 1 tsp coarse kosher salt (preferably Diamond Crystal)
• ¼ tsp freshly ground white pepper
• Pinch of freshly grated nutmeg