Preheat your oven to 375°F. In a large pot, boil salted water and cook the lasagna noodles according to package instructions until they are al dente. Transfer the noodles to a bowl of cold water.

In a large skillet over medium-high heat, add the ground beef and cook until browned, about 5-7 minutes. Drain any excess fat, then add diced onions and sauté until softened.

Stir in minced garlic, salt, pepper, and oregano; then pour in the marinara sauce. Simmer for about 10 minutes until heated through.

In a mixing bowl, combine ricotta cheese, egg, Parmesan cheese, and chopped parsley. Mix until smooth. Add salt and pepper for extra flavor.

Lay out the cooked lasagna noodles flat. Spread a layer of cheese filling on each noodle, followed by a thin strip of meat sauce. Roll each noodle tightly and place seam-side down in a greased casserole dish.

Pour remaining meat sauce over the roll ups and sprinkle with remaining mozzarella. Cover with foil and bake for 40 minutes.

Remove foil and switch oven to broil on high for 2-3 minutes until cheese is golden and bubbly.

Allow the roll ups to cool briefly, garnish with parsley, and serve with a side salad or garlic bread.