I usually do this first: Heat olive oil in a saucepan, saute ground beef until brown, add in the spaghetti/ marinara sauce. Simmer for 10 minutes or more (until everything is ready for assembly).

Meanwhile, boil water in a heavy saucepan for pasta. Add salt, about 2 tbsp. Add the pasta, turn off heat ( I do this to save on gas, the boiling water is enough to pre-cook the pasta) let stand for about 5 minutes; (remember, it will cook some more in the oven so it is important not to cook it through at this stage) drain, set aside.

In the same pot, make the bechamel: melt the butter over low-medium heat. Add the flour and whisk until smooth, about 2 minutes. stirring constantly to avoid lumps, gradually add the milk and continue to whisk until the sauce is smooth and creamy. Simmer until it is thick enough to coat the back of a spoon. This will take approximately 10 minutes. Remove from heat and stir in nutmeg, add 1/2 cup of cheddar cheese, and season with salt and pepper.

Assembly: Add the cooked ziti in the bolognese sauce, toss, then pour in the bechamel. Mix thoroughly using a wooden spoon. Pour into a greased 13 by 9-inch baking dish, smooth out top and sprinkle with mixture of remaining 1/2 cup quickmelt cheese and 1/2 cup mozzarella. Dot the top with diced butter and bake in oven for 25-30 minutes or until bubbling and the top is golden brown.