Preheat a medium-sized pot for about 1 minute over medium heat. Add onion, eggplant, celery, carrot, garlic and Spice Mix. Cook for about 2 minutes, until the veggies begin to soften and get lightly brown, stirring constantly so nothing sticks to the bottom of the pot.
Add the vegetable broth and the lentils to the pot and stir. Bring to a low boil then reduce the heat and simmer for about 30-40 minutes, or until the lentils and veggies are tender.
Carefully pour the veggie / lentil mixture into a 3 quart (2.8 liter) baking dish and remove and discard the bay leaf. Add the garbanzo bean flour and the collard greens to the baking dish and stir until combined.
Preheat your oven to 375°F (190°C) and allow the veggie / lentil mixture to cool while moving on to the next step.
Place the potatoes into large pot and fill with water until they are just covered. Bring to a low boil over medium high heat. Cover the pot and cook the potatoes for about 25 minutes or until they are tender. You should be able to easily pierce them all the way through with a fork.
Drain the potatoes well and transfer to a large mixing bowl with a pair of tongs.
Mash the potatoes with a fork or a potato masher and then add the nondairy milk, nutritional yeast, 1/4 teaspoon salt and about 5 turns of black pepper. Stir until fluffy.
By large spoonfuls, scoop the potatoes and place them on top of the veggie / lentil mixture. Gently spread them out with the back of the spoon so they are evenly distributed and covering all of the veggie / lentil mixture. If you’re feeling fancy, take a fork and lightly rake the tines across the top of the potatoes to make indentations.
Place in the oven uncovered and bake for 20 - 25 minutes, until the potatoes are golden and the filling is bubbling up out of the potatoes.
Let your delicious Shepherd’s Pie rest for about 10 minutes before serving.