Preheat your grill to about 450 degrees and set up for direct heat.
Place the peppers directly over the hottest part of the fire and roast them until they get a nice even char on all sides, flipping them about every 3 minutes to ensure they heat evenly.
When nicely charred and blistered on all sides, remove the peppers to a glass bowl and cover with with Saran Wrap until they are cool enough to handle.
While the peppers are cooling, grill the eggplant on the hot grill, for about 5 minutes per side, or until the eggplant no longer wants to hold its shape, then remove to a bowl to cool.
When the eggplant is cool, cut a slit in the leathery outer skin and scoop the inner flesh into a food processor.
Peel the blistered skin off of the peppers, and remove the seeds and stems. This may be easier to accomplish under some cold running water. Add the pepper to the food processor along with the remaining ingredients and pulse to a relish consistency. Don't over blend it.
Heat about 1 tablespoon of oil in a small saucepan or skillet, then add the relish and cook for about 5 minutes until most of the liquid is cooked off.
Remove the relish to a bowl and let cool. Refrigerate until needed.