Preheat the grill to full whack and place a large tray on a shelf close to the heat. Trim the courgettes and aubergine, slice lengthways into ½ cm pieces, then place in a bowl. Sprinkle generously with sea salt and toss, then put aside. Pick the basil leaves, set aside and finely chop the stalks. Peel and finely chop the garlic. Heat ½ tablespoon of olive oil in a medium saucepan over a medium heat, add the garlic and basil stalks, then fry gently for 2 minutes before adding half the tomatoes (save the rest of another day) and the same volume of water. Cook for 10 minutes, or until it reaches a saucy consistency. Meanwhile, rinse the courgette and aubergine, then pat dry with kitchen roll. Tip back into a bowl and toss with 1 ½ tablespoons of olive oil, and a good pinch of seasoning. Spread the courgette and aubergine on the hot tray and slide under the heat (you may need to do this in batches, as you want the veg in one layer). Grill for 5 minutes, or until browned, then flip the veg grill for a further 5 minutes. Keep an eye on the veg as it grills, then tip into a bowl. Taste and season the sauce, then pour over the vegetables. Tear over the basil leaves and mix. Spread evenly on the tray and tear over the mozzarella. Sprinkle with breadcrumbs and grate over the Parmesan, then slide back under the grill. Grill until the cheese has melted. Meanwhile, squeeze half the lemon juice into a bowl, add 1 tablespoon of extra virgin olive oil and pinch of seasoning. Mix well, then toss through the rocket. When the parmigiana is bubbling and delicious, divide between plates and serve with the rocket.