Season your lamb shanks well with salt and pepper whilst you preheat a large pot on medium/high (or preheat your slow cooker/pressure cooker if it has a sear function). Place the shanks in and sear them off for a minute on each side to get a bit of caramelization. Note you may need to do 2 at a time, depending on the size of your pot/cooker.
When they’re evenly browned on each side, remove the lamb shanks from the pot/cooker and turn the heat down to medium.
Add your diced onion, garlic, carrot and celery to the pot/cooker with a drizzle of olive oil/ghee to caramelize for a minute.
Now add the zucchini and eggplant in and also pour in the red wine to deglaze the bottom of the pot.
If you were using a pot on the stove, now transfer all of the contents into the slow/pressure cooker.
Add the dried lentils, diced tomatoes, beef broth and brown sugar - then stir well to combine.
Place the lamb shanks into the liquid and set your slow cooker to 8 hours or low OR set your pressure cooker to 45 minutes on high.
When the pressure cooker finishes, allow the pressure to naturally release over 15 minutes.
Serve the braised lamb shanks, vegetables and lentil stew with either mashed potatoes or brown rice on the side.