1. Place eggplant in a non-reactive colander. Salt well, and let sit for at least 20 minutes. In the meantime, make your batter. Combine beer, flour, and your preferred spices, salt and pepper. Whisk together with a fork, but don't stir too much or your lovely beer will go flat.
2. After salting the eggplant, brush off excess salt and press with a paper towel to get rid of the rest of the liquid. I microwave my eggplant for about 3 minutes just to pre-cook it, but I don't think that it's necessary. Heat the oil in a deep fry-pan.
3. Batter and fry the eggplant in batches and drain on paper towels. (This may take a while because you don't want to do too much in the pan at one time)
4. To make the sauce, gently saute the garlic and ginger in the sesame oil. After it's slightly browned, add the hoisin and water to cover. Simmer for 5-10 minutes (adding more water if necessary).
5. Add the soy sauce and scallions. Cook for about another minute, and cool slightly. It should thicken a bit. Serve the fried eggplant with the sauce over top or as a dipping sauce.