Slow Cooker Lasagna

Ingredients

• 2 teaspoons olive oil
• 1 medium onion diced
• 2 pounds ground beef
• 1 pound Italian sausage, casing removed
• 3 cloves garlic, finely chopped
• One 28-ounce can diced tomatoes
• One 14.5-ounce can diced tomatoes
• One 6-ounce can tomato paste
• 1 tablespoon minced fresh basil
• 1 tablespoon minced fresh flat-leaf parsley
• 1 teaspoon dried oregano
• 1/2 teaspoon kosher salt
• 3 cups ricotta cheese
• 3/4 cup freshly grated Parmesan
• 1/2 cup grated Romano
• 1 tablespoon minced fresh basil
• 1 tablespoon minced fresh flat-leaf parsley
• 1/2 teaspoon kosher salt
• 1/2 teaspoon freshly ground black pepper
• 2 large eggs, beaten
• Nonstick cooking spray, for spraying the slow cooker
• 15 uncooked lasagna noodles
• 2 cups grated mozzarella
• Chopped fresh flat-leaf parsley, for garnish