Preheat an outdoor grill for medium-high heat and lightly oil the grate.
Grill eggplant, red bell pepper, poblano pepper, and jalapeno pepper until tender, 20 to 30 minutes. Remove seeds from red bell pepper and poblano pepper. Chop eggplant and peppers.
Pulse eggplant-peppers mixture, green onions, garlic, lemon juice, balsamic vinegar, olive oil, salt, and pepper in a food processor until finely chopped and spreadable.