This is one of our favorites and we (I) always make it around St. Patrick's Day. I originally got the recipe from Rachael Ray, but I have tweaked it over the years because some of the cheese she uses can cost an arm and a leg, and I really don't have any of those to spare. The flavor is just as good and it's always hard to find leftovers of this dish.
Spinach Artichoke Macaroni and Cheese
1 lb whole wheat penne pasta
3 tbsp butter
1 large onion, finely chopped
3 cloves garlic, finely chopped or grated
3 tbsp flour
1/2 cup chicken stock
2 cups milk
1/2 tsp nutmeg
1 box frozen spinach (10 oz), defrosted and wrung dry in a towel.
1 can (14 oz) artichoke hearts, drained and chopped
1 1/4 cup mozzarella cheese
1 1/4 grated parmesan cheese, plus more for top
Preheat oven to 350 degrees. Place a large pot of water over high heat and bring to boil. Salt the water and cook the pasta to al dente, according to package directions. Drain pasta and set aside.
While the pasta is cooking, place another pot over medium-high heat and add butter. Once melted, add the onion and garlic and cook until vegetables are very soft, about 8 minutes. Turn heat up and add flour to the pan. Cook for 1 minute, then whisk the stock into the pan. Whisk in the milk and bring to a bubble. Add the nutmeg, spinach, artichokes, and salt and pepper to taste. Simmer salt until thickened, about 2-3 minutes. Add cheeses and stir until melted.
Toss prepared sauce with cooked pasta and transfer to a casserole dish. Sprinkle more of cheese of the top and bake until the top is golden brown, about 20 minutes.