Place eggplant slices in a single layer on a baking sheet or cutting boards. Sprinkle with salt and leave to sweat for an hour. Turn halfway through and sprinkle the other side. When done, pat dry with paper towels.
Dust the eggplant slices with almond flour on both sides
Over medium heat, add the olive oil, garlic and onion to a cast iron skillet or pan. Sauté until the onions until translucent, about 5 minutes.
Add tomato passata sauce, salt and black pepper. Stir and simmer for 15-20 minutes. Turn off heat.
Preheat oven to 350°F (180°C)
Meanwhile, heat another pan over medium-high heat and add oil. Fry eggplant slices for 2-3 minutes on each side until softened in the center and crispy on the edges.
In a casserole or baking dish, arrange a single layer of eggplant slices. Top each piece with tomato sauce and a portion of mozzarella. When all eggplants have been topped with tomato sauce and mozzarella, create another layer of eggplant slices and repeat the steps.
On the top finished layer, add basil and shredded parmesan
Put the casserole in the oven and bake for 30 minutes, or until the top cheese layers turn golden brown and begin bubbling
Garnish with parsley before serving