In a large non-stick frying pan over medium heat cook the mince, onion and garlic until brown.
Add the pasta sauce, mix well and cook until heated through. Season with sea salt and cracked pepper.
In a large bowl mix together the 3 cheeses.
Line a slow cooker with baking paper.
Spoon a layer of the meat mixture onto the bottom of the slow cooker.
Add a layer of the uncooked lasagna sheets, breaking to fit.
Spread with cheese mixture.
Repeat the layering of sauce, sheets, and cheese until all the ingredients are used.
End with a layer of cheese and an additional sprinkling of Parmesan.
Lay a tea towel under the lid (the tea towel lies between the slow cooker and the lid and acts to absorb condensation).
Cover and cook on LOW for 3 to 4 hours.