01 -
Prepare lasagna noodles according to package directions, drain and set aside.
02 -
Heat olive oil in a large saucepan over medium heat. Add ground beef and break into small pieces. Cook until no longer pink, about 5 minutes. Add chopped onion, minced garlic, oregano, basil, salt, and pepper; cook until onion is translucent, about 5 more minutes. Stir in diced tomatoes and tomato sauce, bring to a boil. Reduce heat and simmer for 30 minutes, stirring occasionally.
03 -
In a medium bowl, combine thawed spinach, ricotta cheese, and shredded mozzarella cheese. Stir thoroughly to combine.
04 -
Set oven temperature to 375°F (190°C).
05 -
Spread a few ladles of meat sauce over the bottom of a baking dish. Lay out cooked lasagna noodles. Evenly spread 2 to 3 tablespoons of the spinach and cheese mixture onto each noodle, then add 1 to 2 tablespoons of meat sauce over it. Roll each noodle tightly and place seam side down in the dish. Repeat for all noodles.
06 -
Pour remaining meat sauce evenly over the assembled roll-ups. Sprinkle 2 cups shredded mozzarella cheese on top.
07 -
Cover dish tightly with aluminum foil and bake for 30 minutes.
08 -
Remove foil and continue baking for an additional 10 minutes to brown the cheese.
09 -
Optionally garnish with fresh basil or parsley, then serve warm.