Get your oven hot, about 400 degrees Fahrenheit (200 degrees Celsius).
To boil, add a little amount of salt to a big pot of water. After the water comes to a boil, add the lasagna and simmer, turning periodically, for about 8 minutes, or until tender but still firm to the biting. Run off.
In a medium saucepan, melt the butter. Add the cream cheese and whisk until the cheese starts to melt, which should take around 5 minutes. Chop some onions and add some salt and black pepper. Cream cheese and warm milk should be whisked together until creamy. Add 1 1/2 cups of Swiss cheese and mix. After the cheese has melted and the sauce has thickened, about 5 to 10 minutes, bring the sauce to a boil and whisk regularly. Take off the stove.
Pour 3/4 cup of cheese sauce onto the bottom of a baking dish that is 9×9 inches in diameter. Top 1/3 of the lasagna noodles with sauce, then top with 1/2 of the cooked chicken and 1/2 of the ham. Dollop 1 cup of sauce over the ham and chicken. Start with half of the remaining lasagna noodles, then add half of the remaining chicken, half of the remaining ham, and one more cup of cheese sauce. Repeat layering as needed. Lastly, add the remaining lasagna noodles, sauce, half a cup of Swiss cheese, bread crumbs, and Italian spice over the top. Place aluminum foil over the dish.
After approximately 25 minutes of baking in a preheated oven, the casserole should be bubbling. After 10 more minutes of baking without foil, the crumbs should be golden. Allow the dish to rest for 5 to 10 minutes before to consumption.
