Cut eggplant into 1/2 inch thick slices and lay the slices out on a baking sheet. Generously salt the slices and set aside.
Preheat oven to 175 degrees Celsius (350 degrees Fahrenheit)
After 20 minutes, beads of liquid should have formed on the surface of the eggplant, rub the tops of each with a paper towel to remove moisture as well as the excess salt
Brush each eggplant with olive oil and place in oven for 20 minutes flipping after the first 10 minutes
In a pot over medium heat sauté onions and minced garlic for 5-6 minutes until onions become translucent
Lower heat to medium low and add tomatoes, oregano and parsley and season with salt and pepper. Let simmer uncovered for 20 minutes, if mixture begins to look dry add a splash of white wine.
Top each eggplant slice with a spoon full of the tomato mixture and a few crumbled pieces of feta. Bake in the oven for 10 minutes until the cheese begins to look soft
Remove from oven, top each with a basil leaf and serve