Finely chop the sweet onion.

Dice the carrots.

Mince the garlic.

Peel and chop the potatoes.

Sauté the chopped onion in margarine in a large pan over medium heat until translucent (about 4 minutes).

Add the Italian herbs, dried sage, bay leaves, salt, pepper, garlic, and diced carrots to the pan.

Sauté for an additional 5 minutes.

Add the vegetable stock and dried lentils to the pan.

Bring the mixture to a boil, then reduce heat and simmer for about 20 minutes, or until the lentils are slightly softened and most of the stock is absorbed.

Remove the bay leaves from the lentil mixture.

Stir in the corn, peas, balsamic vinegar, and ketchup (if using).

Pour the lentil mixture into an 8 x 10 inch dish.

Set the lentil mixture aside.

Boil the chopped potatoes in water until softened.

Drain the water from the potatoes, keeping the potatoes in the pot.

Mash the potatoes along with margarine, salt, pepper, and milk.

Add milk until you reach your desired consistency.

Spread the mashed potato mixture evenly on top of the lentil mixture in the dish.

Bake in a preheated 350 degree F (175 degree C) oven for 25 minutes.

Let the pie stand for 5 minutes before serving.

Serve as is, with ketchup, or barbecue sauce.