Sprinkle the eggplant with the ½ tablespoon fine sea salt and place in a bowl. Set aside for 10 minutes. Preheat the barbecue for direct cooking.
Rinse the eggplant well to remove all the salt. Dry the eggplant thoroughly. Put the eggplant, zucchini, and capsicum in a large bowl, mix with 1 tablespoon olive oil, and season salt and pepper. Once the barbecue is preheated, turn all burners to medium.
Place the vegetables directly on the grill leaving a small gap between each piece. Close the lid and cook the vegetables for 3 to 5 minutes per side. Remove from the grill.
To assemble each stack, lay a piece of eggplant on a plate. Crumble some of the goat cheese on top of the eggplant. Lay a couple of slices of zucchini on top. Crumble some more goat cheese on top of the zucchini. Lay a slice of the capsicum over it. Repeat this process to create the stacks.
In a small bowl whisk 1 tablespoon olive oil with the lemon juice and season with salt and pepper. Add the rocket leaves and toss. Drizzle with balsamic glaze and sprinkle with the toasted pine nuts.