Simply The BEST Homemade Lasagne Recipe

Name: Simply The BEST Homemade Lasagne Recipe
Prep time: 30 min
Cook time: 2 h 45 min
Total time: 3 h 15 min
Cuisine: Italian
Ingredients: 2.2lb / 1kg Ground/Minced Beef ((see notes)); 3.5oz / 100g Pancetta, (finely diced); 2 cups / 500ml Tomato Passata ((Pureed Tomatoes in US)); 2 cups / 500ml Beef Stock; 1 cup / 250ml Red Wine; 2 ribs of Celery, (finely diced); 2 medium Carrots, (grated on a box grater); 1 large White Onion, (finely diced); 3 cloves of Garlic, (finely diced); 2 tbsp Tomato Puree ((Tomato Paste in US)); 2 Bay Leaves; 1 small bunch EACH: Fresh Basil, Fresh Parsley (finely diced (approx 1oz/30g each)); 1 tsp Dried Oregano; 1.5 tsp Sugar, (or to taste); Salt & Pepper, (to taste); Olive Oil, (as needed); 4 cups / 1 litre Milk, (at room temp); 5 tbsp Plain Flour ((60g)); 4 tbsp Butter ((60g)); 1/2 small Nutmeg, (finely grated); 1 cup / 80g freshly grated Parmesan (); 12oz / 350g Fresh Lasagne Sheets ((see notes)); 2 cups / 200g Mozzarella, (shredded); 1/2 cup / 40g freshly grated Parmesan