Chicken Manicotti

1 small chopped onion (any kind you like)
2 cloves minced garlic
2-4 boneless skinless chicken breasts or tenders, chopped (marinated in Italian dressing, optional)
olive oil or butter or a mixture
Saute onions for a few minutes then add the garlic and chicken, brown chicken for about 7 minutes on medium heat. After browning chicken add pk. of softened cream cheese and melt into chicken mixture. Add 1 cup of frozen spinach (thawed and drained well) and simmer for 5 minutes, stirring frequently. Set aside. Whisk one egg until lightly beaten, add 1 15 oz. tub of ricotta cheese (can substitute cottage cheese if necessary), 1 1/2 cups of shredded mozzarella cheese, and 1/2 cup of shredded parmesan cheese (parmesan/romano/mixture....optional). Use electric mixer to blend egg and ricotta, then fold in the other cheeses, adding a little salt and pepper before folding. Stir chicken and cheese mixtures together. (I didn't use all of the chicken mixture) Fill a large resealable bag with the mixture, squeezing out most of the air. Snip a hole in a corner of the bag and squeeze mixture through whole into cooked (according to package) and rinsed (with cold water) manicotti shells. I filled 14 manicotti shells with this recipe. Line the bottom of a casserole dish with about 1/2 cup of your favorite spaghetti sauce (or you can even use alfredo). Layer the manicotti shells, then drizzle with remainder of sauce. Cover with foil and bake at 350 for 40 minutes. Sprinkle with more shredded mozzarella in last 10 minutes of cooking (optional). Garnish with fresh parsley, basil, or cilantro. (optional)