• In a saucepan, melt 2 tablespoons of butter and then add ¼ cup of flour. Stir until thoroughly combined and a paste has formed.
• Add 2 cups of milk and ⅔ cup of pesto, stirring until the mixture is smooth. Allow the sauce to come to a simmer for about a minute and then turn off the heat. Let it sit until cooled
• In a seperate bowl, combine 15 oz of ricotta cheese and 1 egg with ½ teaspoon of salt and 1 tsp of black pepper. Mix until thoroughly incorporated.

Lasagna Assembly

• Preheat the oven to 375 degrees.
• Spoon about a quarter cup of the pesto sauce mixture into the bottom of a 9x13 pan. The remaining pesto sauce will be divided into thirds. Lay the lasagna noodles in the pan, breaking noodle pieces to cover the bottom of the pan if necessary.
• Spread half of the ricotta cheese mixture onto the noodles. Spread half of the cooked chicken over the ricotta cheese mixture and then 1 cup of mozzarella cheese over that. Next pour ⅓ of the remaining pesto sauce over the pan.
• Layer more lasagna noodles and then repeat the previous step.
• Next, lay the final layer of lasagna noodles. Then pour the last third of the pesto sauce and cover with the last cup of mozzarella cheese. Cover the pan with tin foil and place in the preheated oven for 30 minutes.
• After 30 minutes, take the tin foil off and continue to bake for 15-20 minutes until the cheese is fully melted and lightly browned on the top.
• Let the lasagna rest for about 15 minutes before cutting into and serving.