Preheat oven to 350 degrees F.

In a large skillet, melt half of the butter over medium heat. Add turkey and cook until browned. Add tomato sauce, oregano, parsley, salt, pepper, and onion and simmer until onion is tender.

Cook pasta in a large pot of boiling, salted water until a little less than al dente. Drain and cool. Cut 1 of the blocks of cheese into cubes and slice the other into thin slices. Melt the remaining butter and pour into the bottom of a deep 9 by 13-inch baking dish. Pour 1 1/2 ladles full of the sauce into the dish, or enough to completely cover the bottom. Add a layer of pasta and then a layer of cubed cheese. Repeat layering until all ingredients are used.

Fill 1 of the empty sauce jars 1/8 full with water and shake. Pour over pasta. Top with the thin slices of cheese, and sprinkle with additional oregano and parsley, if desired. Cover casserole with foil and place in oven. Check every 15 minutes until cheese is melted and bubbly. Remove foil for last 5 minutes of cooking to brown cheese.