Whisk the flax seeds and water together in a small bowl, then allow the mixture to sit for at least 10 minutes.
While the flax mixture sits, heat 1 tablespoon of olive oil in medium skillet over medium heat. Add the onion and sauté until soft and translucent, about five minutes. Add the garlic and continue to sauté until very fragrant, about 1 minute more.
Add the eggplant and continue to cook for about an additional 10-15 minutes, flipping occasionally, or until the eggplant is soft and browned in spots. Allow to cool.
Preheat the oven to 375° and coat a baking sheet or large cast iron skillet with the remaining tablespoon of oil.
Place the eggplant mixture into a large mixing bowl, along with the flax mixture, and stir in all remaining ingredients. Mix well (hands work great here), and then shape the mixture into 1-inch balls (about 20 of them).
Arrange the meatballs on the baking sheet or in the skillet and bake for 30-35 minutes, turning once or twice during baking in order to brown all sides.
While these are great served with sauce, I don't recommend storing or letting them sit in the sauce for too long, as they're pretty delicate and will fall apart.