01 -
Set oven temperature to 375°F (190°C).
02 -
Boil lasagna noodles in salted water according to package directions until al dente. Drain and set aside.
03 -
In a 4-quart saucepan over medium heat, melt butter. Whisk in flour, black pepper, sea salt, garlic powder, and onion powder. Cook, stirring constantly, for 1 to 2 minutes until mixture is browned and bubbly.
04 -
Gradually whisk in whole milk to the roux until smooth. Continue cooking over medium heat, stirring, until the sauce reaches a gentle boil and thickens, about 6 to 8 minutes.
05 -
Add sliced cream cheese and ½ cup shredded jack cheese to the sauce. Stir until fully melted and combined. Remove from heat.
06 -
Fold baby spinach leaves into the white sauce and set the mixture aside.
07 -
In a small bowl, mix ricotta cheese, beaten egg, dried or fresh parsley, and ½ cup shredded jack cheese until smooth.
08 -
Lightly grease a 9x13-inch glass baking dish. Spread a thin layer of white sauce to cover the bottom. Layer three lasagna noodles side by side over the sauce.
09 -
Spread half of the ricotta mixture evenly over the noodles. Distribute half the cooked chicken atop. Spoon one-third of the white sauce over the chicken and ricotta. Sprinkle with 1 cup mozzarella and 1 cup jack cheese.
10 -
Arrange another layer of noodles. Spread the remaining ricotta mixture followed by the remaining chicken. Top with 1 cup each of mozzarella and jack cheese.
11 -
Add the final layer of noodles. Cover with the remaining white sauce and finish by sprinkling the last portions of mozzarella and jack cheese evenly on top.
12 -
Bake in preheated oven for 30 to 35 minutes, until sauce is bubbling and cheese is melted and lightly browned.
13 -
Remove from oven and optionally garnish with additional parsley before serving.