There are lots of dishes which combine pasta, a meat sauce, and bechamel sauce, such as the Greek pastitsio (One Pot Pastistio) and the Egyptian Macarona Bechamel.  In this group is the Italian-American Million Dollar Spaghetti, which was recently touted by SeriousEats.  Here is how I made it based on their recipe.  This takes less than 2 hours to prepare and makes 8-12 servings.  (We cut it into 10 pieces.)  It is very kid friendly.

For the meat sauce

2 Tbs. olive oil

1 medium onion (~8 oz.), chopped

1 lb. ground beef

½ lb. Italian sausage, removed from casing

4 cloves garlic, chopped

3 Tbs. tomato paste

2 tsp. fish sauce

1 tsp. dried oregano

1 dried bay leaf

¾ tsp. salt

½ tsp. freshly ground black pepper

¼ tsp. crushed pepper flakes

1 (28 oz.) can crushed tomatoes

½ cup water (use to rinse out the crushed tomato can before adding to the pot)

For the Béchamel

5 Tbs. unsalted butter

1/3 cup all-purpose flour

2-1/2 cups whole milk

4 oz. low moisture mozzarella, shredded

1 oz. Parmesan cheese, grated (about ¼ cup packed)

¼ tsp. ground nutmeg

½ tsp. salt

¼ tsp. freshly ground black pepper

For the Spaghetti

1 lb. dried spaghetti (I used bucatini)

2 Tbs. unsalted butter

Cooking spray

3 oz. grated Parmesan (about ¾ cup packed)

Start by making the meat sauce.  In a large Dutch oven heat the oil over medium-high heat.  Add the onions and cook until translucent.  Push the onions to the edge of the pot and add the ground beef and Italian sausage.  Brown the meat and break it into small pieces.  Add the garlic and tomato paste and fry them for a minute or so.  Add the remaining sauce ingredients.  Bring to a boil, reduce to a simmer, and cook uncovered for 30-40 minutes.  Stir occasionally and break up the meat into small pieces.  Check for seasoning.

While the meat sauce is cooking, make the béchamel sauce.  In a medium saucepan, melt the butter over medium-high and cook the flour for a couple of minutes, whisking frequently.  Slowly whisk in the milk to make a smooth mixture.  Cook until the mixture thickens slightly and can coat the back of a spoon.  Remove from the heat and stir in the cheeses, nutmeg, and salt and pepper.  Check the seasoning.  Can be used immediately.  If prepared in advance, cover the surface with plastic wrap to avoid a skin being formed.

Preheat the oven to 350 degrees.  Coat a 13 x 9 inch lasagna pan with cooking spray and put it on a cookie sheet. 

In a large pot of salted water cook the pasta to 1 minute before it is al dente.  Drain the pasta and put it in a large bowl with the butter.  Stir to coat the pasta with the butter.  Add ¾ cup of the béchamel and stir to coat the pasta.

Put the coated pasta in the baking pan.  Then add the meat sauce in an even layer, then the béchamel and last the Parmesan.  The pan will be very full.  Put in the oven uncovered and bake for 30-40 minutes until it is heated through, bubbly and the top is golden brown.  If it could use more browning, turn on the broiler and broil it for a couple of minutes.

Remove from the oven and allow to rest for 10-15 minutes before cutting up and serving it.