Lightly salt the sliced eggplant on both sides, and let rest for at least 30 minutes. Once the eggplants release liquid, pat dry.
Apply the Serious Foodie Sicilian Spice Blend to both sides of the eggplant. Brush on the garlic oil on both sides.
Salt and pepper the tomato slices and onion slices to taste, and then brush both sides with either olive oil or garlic oil. Rub some olive oil onto the surface of the red bell peppers.
Preheat grill to medium-high. Grill the tomatoes, onions, and red bell pepper until charred in spots, 4 to 5 minutes. Transfer to a cutting board. When cool enough to handle, remove the skin off the bell peppers, then remove the core. Roughly chop the tomatoes, onions, and roasted peppers and transfer to a bowl.
Grill the eggplant rounds, turning once, until lightly charred in places and almost tender, 4 to 5 minutes per side. Transfer to a plate.
Top eggplants with mozzarella. Return to grill and cook, covered, until cheese melts, 1 to 2 minutes. Top evenly with tomato/onion/pepper mixture, sprinkle with Parmigiano Reggiano and basil, drizzle with olive oil.
