In response to a
request about how to make fresh squeezed orange juice.It takes a little
work,but it tastes much better than orange juice from concentrate.
Bring a large pot of lightly salted water to a boil.Add ziti pasta,and cook until al dente,about 8 minutes; drain.
In a large skillet,brown onion and ground beef over medium heat.Add spaghetti sauce,and simmer 15 minutes.
Preheat the oven to 350 degrees F(175 degrees C).Butter a 9x13 inch baking dish.Layer as follows:1/2 of the ziti,Provolone cheese,sour cream,1/2 sauce mixture,remaining
ziti,mozzarella cheese and remaining sauce mixture.Top with grated Parmesan cheese.  
Bake for 30 minutes in the preheated oven,or until cheeses are melted.