Heat the half and half in a small saucepan over medium-low heat until simmering. You can also use the microwave, if you prefer.
In a medium saucepan, melt the butter. Whisk in the flour and cook over medium heat for about 2 minutes whisking constantly.
Gradually, pour the warm half and half into the butter/flour mixture whisking constantly. Continue cooking stirring frequently until the mixture thickens, about 5 – 6 minutes. Add the nutmeg, salt and ground black pepper to taste.
Stir in ¾ cup of Parmesan cheese and about ½ cup of the meat sauce. Mix to combine and remove from the heat. Allow the béchamel sauce to cool for about 10 minutes, then quickly stir in the eggs, whisking constantly. Add the yogurt and mix to combine. Set aside.
Meanwhile, cook the pasta in a large pot of salted boiling water until just al dente. Don't over-cook the pasta as it will have to bake later. Drain.
Mix the cooked pasta with the meat sauce and pour the mixture into a large baking dish (9.5 x 13).
Spread the bechamel evenly to cover the pasta and sprinkle with the remaining 3/4 cup of Parmesan cheese.
Bake for 1 hour, until golden brown and bubbly. Remove from the oven and set aside for 10 minutes before serving.