Rollatini with spinach and artichokes

Ingredients:

Cheese sauce

• 4 tablespoons unsalted butter
• 1/4 cup flour
• 4 cups whole milk
• 1/4 tsp cayenne pepper
• 1 cup grated cheddar (about 100 g)
• 3/4 tbsp. grated mozzarella (about 90 gr.)
• 3/4 cup grated Parmesan (about 90 g)

Filling

• 2 tablespoons unsalted butter
• Half a small onion, finely chopped
• 1 package (280g) frozen chopped spinach, thawed and squeezed out of water
• 1 package (250g) frozen artichoke hearts, thawed and squeezed out of water
• 1 teaspoon Worcestershire sauce
• 1/4 cup grated Parmesan (about 30 g)
• 1 large egg

Rollatini

• 1 tbsp extra-virgin olive oil
• 12 lasagna sheets, regular
• 1 tbsp. grated mozzarella (about 100 gr.)
• 1 tbsp. l. grated parmesan

Preparation:

1. Prepare the cheese sauce:
   
   Melt the butter in a medium saucepan over medium heat. Stir in the flour until smooth; cook, stirring, for 1 minute. Gradually whisk in the milk and cayenne pepper until smooth. Bring to a simmer and cook, stirring occasionally, until the sauce thickens slightly, about 2 minutes. Remove from heat and stir in the Cheddar, mozzarella, and Parmesan until melted. Season with 1/2 teaspoon salt and a few grinds of black pepper; let cool to room temperature, about 1 hour.
2. Prepare the filling:
   
   Melt the butter in a skillet over medium heat; add the onion and cook, stirring occasionally, until softened, about 6 minutes. Add the spinach, artichoke hearts, Worcestershire sauce, and 1/2 teaspoon salt and cook, stirring occasionally, until the vegetables are tender, about 5 minutes. Transfer to a bowl and let cool for 30 minutes. Season with salt and pepper, then stir in the Parmesan, egg, and 3/4 cup of the cooled cheese sauce.
3. Preheat oven to 175°C.
4. Prepare rollatini:
   
   Bring a large pot of salted water to a boil. Add the noodles and cook, stirring frequently, until tender but not completely soft, about 8 minutes. Drain and rinse the lasagna under cold water until completely cool, then remove to a work surface.
5. Spread 2.5 cups of cheese sauce evenly over the bottom of a 9 x 13-inch baking dish. Spoon 2 tablespoons of the spinach filling onto one edge of each lasagna sheet. Roll up and place seam-side down in the baking dish. Drizzle with the remaining sauce and sprinkle with mozzarella and Parmesan.
6. Cover the pan with foil and bake until the cheese is bubbly, about 35 minutes. Turn the oven to broil. Remove the foil and broil until the rollatini are golden brown, 2-4 minutes. Let rest for 10 minutes before serving.