Make the sauce: In a Dutch oven over medium-high heat, add olive oil and cook onions until translucent, approximately 3 to 5 minutes. Add garlic and saute until fragrant. Add celery and carrots and cook until tender. Add salt and pepper and ground meats. Reduce heat and add tomato paste, whole tomatoes and stock. Reduce to a simmer, and allow to cook for at least 1 hour up to 5 hours.
Assemble the lasagna: In a medium bowl, combine ricotta, eggs, Romano, parsley, salt, pepper and 1/2 pound of mozzarella.
Preheat your oven to 400 degrees. Add approximately 3/4 cup sauce to a 9 by 13 casserole dish, and layer with al dente lasagna pasta. Top with ricotta mixture and cover with pasta. Top with sauce and repeat layers until you reach the top of the casserole dish. Top with remaining mozzarella, and bake for 30 to 35 minutes until cheese bubbles and becomes golden. If desired, broil for 3 to 4 minutes until golden. Allow lasagna to cool for at least 30 minutes before serving. Lasagna will keep up to 5 days covered in the fridge.