Ingredients

• 9 lasagna noodles
  
• 1 tablespoon olive oil
  
• ¾ cup chopped yellow onion
  
• 1 pound ground beef*
  
• Salt and pepper
  
• 3 cloves garlic, minced
  
• 48 ounces marinara sauce (about 6 cups)
  
• 1 teaspoon dried Italian seasoning
  
• ¼ cup chopped fresh parsley
  
• 1 egg
  
• 15 ounces ricotta cheese
  
• 16 ounces shredded mozzarella cheese (about 4 cups)
  
• ½ cup grated Parmesan cheese

Instructions

1. Heat the oven to 375°F.
2. Cook the noodles:
   Bring a large pot of salted water to a boil. Add the lasagna noodles and cook for the shortest time listed on the package. Drain, rinse with cold water, and place the noodles on parchment paper so they don’t stick together.
3. Prepare the meat mixture:
   In a large skillet over medium-high heat, warm the olive oil. Add the chopped onion and cook for 3–4 minutes, stirring occasionally, until softened. Add the ground beef and cook until browned, breaking it up as it cooks. Drain off excess fat. Season with salt and pepper, then stir in the garlic and cook for another 30 seconds.
4. Build the sauce:
   Add the marinara sauce, Italian seasoning, and parsley to the skillet. Stir everything together, bring to a gentle simmer, then reduce the heat to low. Let the sauce cook for 10–15 minutes, stirring now and then.
5. Mix the ricotta filling:
   In a medium bowl, lightly beat the egg. Add the ricotta cheese and combine well. If you haven’t shredded the mozzarella yet, this is the time to do it.
6. Layer the lasagna:
   
   • Spread 1 cup of the meat sauce across the bottom of a 9×13-inch baking dish.
     
   • Place 3 noodles over the sauce.
     
   • Add one-third of the remaining meat sauce.
     
   • Scatter small spoonfuls of half of the ricotta mixture over the sauce.
     
   • Sprinkle one-third of the mozzarella and one-third of the Parmesan on top.
7. Repeat this entire layer once more: 3 noodles, half of the remaining sauce, the rest of the ricotta, and half of the remaining mozzarella and Parmesan.
   
   For the final layer, use the last 3 noodles, the remaining sauce, and the last of the mozzarella and Parmesan.
8. Bake:
   Cover the dish with foil coated on the underside with cooking spray so the cheese doesn’t stick. Bake for 35 minutes. Remove the foil and bake for an additional 10–15 minutes, or until the edges are bubbling and the top is lightly browned. Let the lasagna sit for 10 minutes before cutting.

• If you like, you can include ½ pound of Italian sausage along with the ground beef. Remove the sausage from its casings and brown it together with the beef.
  
• Leftovers keep well in the refrigerator for 3–4 days. The cooked lasagna also freezes nicely for up to 3 months. Thaw overnight in the refrigerator and reheat in the microwave or in a covered dish in the oven until piping hot.
  
• To prep ahead: Assemble the lasagna completely, cover it, and refrigerate for up to 24 hours before baking. If baking straight from the fridge, increase the covered bake time by about 15 minutes.
  
• To freeze before baking: Wrap the assembled lasagna tightly and freeze for up to 3 months. Thaw for 24 hours in the refrigerator before baking, and add roughly 15 extra minutes to the covered baking time.