Heat the grill to medium-high. Cut the eggplant into ½-inch thick slices. Cut the bell pepper in half. Cut the onion into ¼- to ½-inch slices (leave the rings intact). Rub the vegetables lightly with olive oil.
Grill the vegetables for 20 minutes, flipping once or twice, until tender.** Once cool enough to handle, transfer the vegetables to the bowl of a food processor.
Add the black beans and lime juice. Process on high for about 20 seconds, until the veggies and beans are chopped fine and maintain a spread-like consistency.
Add the chile powder, cumin, cayenne pepper, 1 teaspoon salt, and cilantro. Pulse until all the spices are mixed in and the cilantro is finely chopped. Taste and add the additional ½ teaspoon of salt if desired.
Serve immediately, or refrigerate in a sealed container for up to one day.
*We recommend using lemons and limes from Paramount Citrus. They are consistently fresh and juicy and available at most major grocery, mass and club retailers.
**This dip can also be made in your oven. Place the vegetables on a baking sheet and roast at 425°F for about 20 minutes, flipping once halfway through.