Assembling the lasagna involves alternating layers of the bechamel sauce, lasagna noodles, and the red (meat) sauce.
Preheat the oven to 350° Fahrenheit (175° Celsius).
Lightly spread a 9x13 baking dish with some of the bechamel sauce.
Add a first layer of the lasagna noodles.
Cover with about 1/3 of the meat sauce.
Layer more lasagna noodles on top.
Add a thicker layer of the bechamel sauce.
Sprinkle on some of the mozzarella cheese and the Parmesan cheese.
Layer more lasagna noodles on top.
Add another layer of the meat sauce and cover with another layer of lasagna noodles.
Spread on another layer of the bechamel sauce and the cheeses.
Cover with lasagna noodles.
Spread on the last of the meat sauce. Top with the last of the noodles and add the remaining bechamel sauce and cheeses as the final layer.
Cover with foil and bake for 30 minutes.
Remove the foil and continue baking the lasagna until the cheese is completely melted after about another 5 minutes.
Serve immediately.