Italian Lasagna

Name: Italian Lasagna
Cuisine: European, Italian, Mediterranean
Ingredients: For the meat sauce (ragù); 250g ground beef; 250g ground pork (or veal); 1 small onion, finely chopped; 1 carrot, finely chopped; 1 celery stalk, finely chopped; 400g canned crushed tomatoes (San Marzano if available); 100ml red wine; 2 tbsp olive oil; Salt and freshly ground black pepper (to taste); For the béchamel sauce; 50g unsalted butter; 50g all-purpose flour; 500ml whole milk; Freshly grated nutmeg (a pinch); Salt (to taste); For assembling; 200g lasagna sheets (fresh or dried); 100g grated Parmigiano-Reggiano cheese; Extra virgin olive oil (for greasing)