LasagnaCook the lasagna noodles as per the packages instructions.

FillingIn a large bowl, mix together the ricotta, the -shredded- mozzarella, pecorino romano, egg, kosher salt and ground black pepper. Mix it thoroughly.

AssemblyPoor a little bit of tomato sauce at the bottom of the skillet (just enough to cover the bottom surface).

• Put down your first layer of noodles, covering the bottom of the skillet (approx. 3-4). If the noodles are longer than the skillet, you can trim them a bit or simply fold them over.
• Your next layer will be the ricotta mixture. Spread it evenly over the layer of noodles.
• Spoon some tomato sauce over the ricotta.
• Next, place down another layer of noodles.
• Evenly spread some pesto over that layer of noodles.
• Evenly spread more ricotta mixture over the pesto.
• Place down another layer of noodles.
• Spread more (likely the rest) of the ricotta mixture over the noodles.
• Spoon tomato sauce over the ricotta.
• Put down what will be your last layer of noodles.
• For the top layer, alternate between tomato sauce and pesto for the length of each noodle. This will create a red and green stripe effect for the top layer.
• Finally, place the fresh mozzarella slices on top.
• Place the skillet over medium-low heat for approx. 20 minutes, covered. Let the noodles simmer until cooked through.
• When done, put it under the broiler if you'd like to blister and bubble the top layer of mozzarella (optional).
• Let the lasagna sit for about ten minutes to let it settle. You don't want to cut into it right away.