Created by lazyme on February 24, 2015
Step 1: Heat the oven to 450 degrees F.
Step 2: Oil a 9-by-13-inch baking dish.
Step 3: In a large pot of boiling, salted water, cook the rigatoni until almost done, about 12 minutes. Drain.
Step 4: Put the pasta in the prepared baking dish and toss with 1 tablespoon of the oil.
Step 5: Meanwhile, squeeze as much of the water as possible from the spinach.
Step 6: Put the spinach in a food processor and puree with the ricotta, 3 tablespoons of the Parmesan, the nutmeg, salt, and pepper. Stir in half the fontina. Stir the spinach mixture into the pasta.
Step 7: Top with the remaining fontina and Parmesan.
Step 8: Drizzle the remaining 2 tablespoons oil over the top.
Step 9: Bake the pasta until the top is golden brown, 15 to 20 minutes.
Step 10: You can substitute another chunky pasta, such as penne rigate, ziti, or fusilli. Boil all of these one or two minutes less.