Crisp up the pancetta and set aside
Brown the beef mince in the same pan until it sizzles and colours
Add onion, carrot, celery, garlic, and pancetta back in
Sweat for a few minutes
Stir through the tomato purée and cook for 2 mins
Pour in the red wine and let the alcohol evaporate
Add beef stock, tomatoes, and bay leaves
Simmer gently for 1 hour
Melt butter and stir in flour, cook for 2 mins
Slowly whisk in milk until smooth
Melt through the Boursin and season to taste
Build the lasagne in layers: ragu, sheets, béchamel, mozzarella
Repeat layers
Bake at 200°C/400°F for 35 minutes until bubbling and golden
Rest 15–20 minutes before slicing
