This sounds complicated and time consuming, but isn't.
1 pound ziti with lines 2 tablespoons Extra Virgin Olive Oil 1 medium onion, chopped (can buy pre-chopped in salad section of store) 4 cloves garlic, grated or minced ( 4 tsps. pre-minced garlic in jar if you have it) 1 28 oz. can whole plum tomatoes ( try to get San Marzano) 4-5 leaves basil, torn into tiny pieces 3 tablespoons butter 3 tablespoons flour 2 cups milk 1 fresh or dried bay leaf nutmeg, fresh or grated 1 large ball fresh mozzarella, diced 1/4 cup grated Parmigiano Reggiano
Preheat over 400* F. Place large pot of water over high heat and bring up to boil to cook the ziti. When water boils, add salt and ziti and cook just shy of al dente.
Start the red sauce:
Heat medium size sauce pot over medium high heat with 2 tablespoons of Olive Oil. Add the onion and garlic. Cook about 3-4 minutes until tender. Add tomatoes and smash with potato masher or spoon. Add the basil and season with salt and pepper. Simmer for 15 minutes.
Make the white sauce:
Place a medium saucepot over medium heat and melt the butter. Add flour, mix well and cook for a minute. Whisk in milk and add bay leaf. Season with salt and pepper. Grate fresh nutmeg, 2-3 grates, or a pinch of ground nutmeg. Bring to bubbling, then turn down heat and simmer for 5 minutes, stirring often. Remove the bay leaf.
Drain ziti and place back into pot, add the red sauce and combine. Place in casserole dish and top with the white sauce. Sprinkle mozzarella and grated Parmigiano over the top. Bake for 25 to 30 minutes.