Gently rub the vegetables under cold running water. Peel the potatoes. Then cut up the vegetables into rounds.
Place a pan over medium heat. Heat the oil for frying. Then fry each vegetable separately for 5 to 10 minutes. Take out on a paper towel lined plate and set aside.
Now place a pot over medium heat. Add the olive oil, chopped onions, thyme, garlic and sugar. Saute for 2 to 3 minutes.
Add the mince meat and continue to cook until internal temperature reaches 160°F.
Then add the tomato sauce. Let the sauce thicken then add the seasonings and remove from heat. Now add the herbs then mix well.
In a baking dish layer the potatoes first and season with salt and pepper. Repeat with zucchini and eggplant. Then add meat. Lastly add the Mornay Sauce and spread over the meat. Sprinkle with cheese and herbs, if using. Now bake for 40 minutes. Remove and let it cool down a bit.