Heat your grill to high. Brush the eggplant, onion slices and tomatoes with olive oil and season each type of vegetable with salt and pepper, to taste.
Grill the eggplant for 6 to 8 minutes per side until golden brown and cooked through. Grill the onions for 3 to 4 minutes per side until golden brown and just cooked through. Grill the tomatoes for 2 minutes per side until charred and slightly soft. Remove to a cutting board and cut into quarters.
Remove the vegetables from the grill to a cutting board and cut into 1/2-inch pieces. Transfer the vegetables to a medium bowl and add the olives, capers, raisins and pine nuts.
Mix together the garlic, red pepper flakes, vinegar and honey in a small bowl and season with salt and pepper, to taste. Slowly drizzle in 1/4 cup of olive oil and whisk until emulsified.
Pour the dressing over the vegetables, add the parsley and stir gently to combine. Let the salad sit at room temperature for at least 30 minutes and up to 2 hours before serving.