First, preheat the oven to 375 degrees F. Then, lightly grease a 9x13 baking dish with olive oil or with non-stick cooking spray. Set aside.
Cook pasta per box directions, drain, drizzle with some olive oil.
Place a large skillet over medium heat, add butter, and melt.
Once melted add flour and stir until fully combined, cook for 1-2 minutes.
Next, add the milk slowly, whisking continuously until fully mixed. Let it come to a simmer.
Reduce heat to low, add salt, pepper, paprika, and garlic powder. Stir to combine, taste, and adjust.
Turn off heat and add shredded mozzarella, stir until fully melted.
Add cooked pasta to a large bowl, add cubed chicken and cubed ham. Add cheese sauce and stir until well combined and the ingredients are evenly coated.
Transfer the mixture to the prepared pan and level the top with a spatula.
Top with the shredded Swiss cheese.
Bake uncovered in the preheated oven for 25-30 minutes, until the cheese on top is lightly golden-brown and the mixture is bubbling.
Remove from oven, let it stand for 10 minutes, and garnish with freshly chopped parsley before serving.