2 cups (500 ml) dried fettucine
3 cups (750 ml) roasted chicken, roughly chopped
¼ cup (60 ml) butter
1 onion, diced
3 cloves garlic, minced
1 cup (250 ml) heavy cream
1 cup (250 ml) Parmesan cheese, shredded, divided
1 cup (250 ml) sour cream
1 cup (250 ml) ricotta cheese
2 eggs, beaten
½ cup (125 ml) frozen peas
Salt, to taste
Freshly ground black pepper, to taste
Preheat oven to 400 degrees Fahrenheit (200 degrees Celsius).
Bring a large pot of water to a rapid boil over high heat. Generously salt, and add dried fettucine noodles. Cook for 7 minutes, or until the noodles are al dente. Drain, rinse with cold water to stop the cooking process, and place in a large bowl with the chicken.
While the noodles are cooking, melt butter in a frying pan set over medium heat. When melted add the onions and saute for 2 minutes, just until the onions have softened. Add the garlic, stir, and cook for another 30 seconds.
Lower the heat and slowly whisk in the heavy cream. Season with salt and a generous helping of freshly ground black pepper. Let cook for 5 minutes or so, just until thickened. Stir in ½ cup (125 ml) Parmesan cheese and stir until melted. Set aside and let cool slightly.
Add the sour cream, ricotta cheese, egg, frozen peas, and Alfredo sauce to the noodles and chicken in the large bowl. Stir to thoroughly combine all ingredients.
Pour into a 9" x 13" casserole dish and top with remaining ½ cup (125 ml) Parmesan cheese.
Cover dish with aluminum foil and bake in the oven for 30 minutes. Remove foil and bake for another 10 minutes or so, just until the cheese has melted and started to brown slightly.