Ignite all of the burners to medium-high and leave with the lid closed until the temperature gauge is at roughly 260°C, then turn off the left-hand burners to create an indirect heat cooking zone. Place the couscous in a metal bowl with a pinch of sea salt, finely grate over half the lemon zest and just cover with boiling kettle water. Cover and leave for 10 minutes, then fluff with a fork. Quarter the aubergine and courgette lengthways then place on a large board seasoned with salt. Season the top layer, then leave for 15 minutes. Chop the unpeeled onion into quarters. Finely grate the remaining lemon zest into a small bowl and put aside, then cut the lemon in half. Place the lemon halves, onions and peppers on the right-hand side (hot) of the grill cut-side down for 10 minutes, then move the onions and lemons to the indirect heat and continue cooking with the lid closed for 30 minutes, or until tender, turning occasionally. Transfer the peppers to a board, then once cool enough to handle, remove the stalks and seeds. Brush the aubergines and courgettes lightly with olive oil and grill on the right-hand side (hot) for 10 minutes, or until golden all over, removing to a board as and when it’s ready. Discard the onion skin. Keep 4 of the peppers to one side, then roughly chop the remaining peppers with the rest of the grilled veg. Meanwhile, place the feta on a piece of greaseproof paper inside a small barbecue-safe baking dish and top with the reserved lemon zest. Strip over the thyme or oregano leaves, drizzle with a little honey and olive oil, then place on the right-hand side (hot) for 10 minutes, or until golden at the edges. Place the reserved peppers into a blender with 3 tablespoons of extra virgin olive oil, then peel and add the garlic clove, along with 1 teaspoon of red wine vinegar and a pinch of black pepper. Squeeze one half of the jammy lemon into the blender, whiz until smooth, then taste and season to perfection. Pick and finely chop the mint and parsley, reserving a few small leaves to garnish, and toss through the couscous with the chopped veg. Squeeze over the remaining jammy lemon, drizzle with the pepper dressing and break over the feta. Hold the pomegranate half cut-side down in your fingers and bash the back of it with a spoon so the seeds tumble over the couscous. Scatter over the reserved herb leaves, then bash and sprinkle over the pistachios, to serve.