Step 1

Preheat oven to 350 degrees F. Coat 6 individual gratin dishes or a 1 1/2-quart shallow baking dish with cooking spray. Put a large pot of water on to boil for cooking pasta.

Step 2

Heat oil in a large saucepan over medium heat. Add flour and cook, whisking constantly, for 1 to 2 minutes. Add hot milk and bring to a simmer, whisking, until smooth and slightly thickened, 3 to 4 minutes. Remove from heat and add 1/4 cup fontina and nutmeg, stirring to melt the cheese. Season with salt and pepper.

Step 3

Meanwhile, cook tortellini until just tender, 6 to 8 minutes or according to package directions. Drain and rinse well.

Step 4

Combine the tortellini with the cheese sauce and toss. Transfer to the prepared dishes or baking dish. Top with the remaining 1/4 cup fontina. Combine breadcrumbs and Parmesan and sprinkle evenly over the tortellini.

Step 5

Bake the tortellini until golden and bubbly, 15 to 25 minutes. Serve immediately.