Heat olive oil in a large deep skillet over medium heat.
Add the chopped onion and cook for 3-4 minutes until softened.
Add the minced garlic and cook for 1 minute until fragrant.
Add the ground beef to the skillet and cook, breaking it apart with a spoon, until browned and cooked through, about 6-8 minutes.
Stir in the dried oregano, dried basil, salt, and black pepper.
Pour in the marinara sauce and stir to combine.
Add the broken lasagna noodles and water to the skillet, stirring to submerge the noodles in the sauce.
Bring the mixture to a simmer, cover the skillet, and cook for 15 minutes, stirring occasionally, until the noodles are tender and have absorbed most of the liquid.
Meanwhile, in a small bowl, combine the ricotta cheese, egg, and grated Parmesan cheese.
Remove the skillet from heat and dollop the ricotta mixture evenly over the noodles.
Sprinkle the shredded mozzarella cheese evenly over the top.
Cover the skillet again and let it sit for 5 minutes off the heat to allow the cheese to melt.
Garnish with chopped fresh parsley before serving.