STEP - 1
Preheat oven to 350°.
STEP - 2
In a large pot of salted boiling water, cook lasagna noodles according to package directions until al dente. Drain and transfer to a baking sheet to cool.
STEP - 3
Meanwhile, in a large skillet over medium heat, melt butter. Add garlic and cook until fragrant, 1 minute, then add flour and cook 1 minute more. Pour in milk and season with salt and pepper. Bring to a simmer and let thicken, 2 to 4 minutes. Add Parmesan and stir until creamy, then add chicken, spinach, and artichokes and stir until combined.STEP - 4
Assemble lasagna: Spread a thin layer of chicken mixture in a large baking dish and top with a layer of overlapping noodles. Spread a layer of ricotta over the noodles, add a layer of chicken mixture, and sprinkle with a layer of mozzarella.
STEP - 5
Repeat for three layers total, ending with mozzarella.
STEP - 6
Tent with foil and bake for 35 minutes.
STEP - 7
Remove foil and bake until browned and bubbly, 10 minutes more.
STEP - 8
Let cool for 15 minutes before slicing and serving