This is my take on both a bolognese (ragu) sauce as well as aubergine parmigiana.
First, get some good quality beef mince, roughly 100g per person. You need to brown the mince well. This will add both a richer colour and more flavour. Once the mince has turned from red to grey quite often there is a lot of fat and water. Drain all of this off in a sieve so that it browns and doesn’t boil in the liquid. Place back in the pan and add some olive oil and then brown so that there are visible caramelised brown bits (flavour) like you get on a steak.
When done place into a bowl for later or better yet straight into a slow cooker. Next chop a couple of onions and a few cloves of garlic, sauté these until soft and slightly caremelised. I also added finely chopped celery and carrot. Then ‘de-glaze’ all the good crispy bits (flavour) with 1/4-1/2 bottle of red wine and reduce this by half. Stir and make sure you clean the bottom of the pan with a wooden spoon, then add this to the mince and vegetables.
Add all the ‘wet ingredients’ incl beef, onions, garlic, carrot and celery mix together and put in two tins of plum tomatoes. Before you add the tomatoes if you have a hand whizzer blend these to a fine ‘passata’ and add to the mix (but it’s by no means a deal breaker). Season with salt and pepper and add a teaspoon of sugar. Tomatoes are acidic and so salt and sugar helps to balance the sauce. The mix is now ready to slow cook for 4-8 hours. A slow cooker is great but otherwise a big saucepan with a lid (or tightly cover with aluminium foil) and place it on a cooker hob on the lowest setting or in an oven at 150 degrees C.
This is the ragu done. If you want you can add mushrooms and if I was cooking a bolognese I would have 50:50 pork and beef mince but otherwise this is my recipe for a slow cook bolognese.
Meanwhile pre-heat your oven (to 180 degrees C) and slice aubergines lengthways just under a cm thick. Place on a baking tray and generously drizzle with olive oil and season with S&P. They probably need 20 minutes until they are brown. Check after 15 and turn if necessary.
Once the mix has slow cooked and the aubergines are done you need to layer up with mince, aubergine, mozzarella and parmesan at each layer. Something like this….
I also add sliced tomatoes to the top and cover generously with mozzarella and parmesan. Then bake for 30-45 minutes at 180 degrees C or until nice and golden brown.