Heat a griddle over a high heat. Mix 1 tbsp oil with the thyme and seasoning, and brush over the lamb chops. Cook the chops for 3-4 mins each side, then stand them up and griddle the fat for 1-2 mins. Remove to a plate, wrap in foil and leave to rest.
Brush the courgettes with the remaining oil and season. Griddle for 2-3 mins each side until they are soft and have griddle marks – you may need to do this in 2 batches. Meanwhile, cook the mangetout for 2-3 mins in a medium pan of boiling water. Drain and tip into a large bowl with the courgettes. To make a dressing, mix the vinegar, mustard, chilli flakes (if using), mint and basil. Toss the courgettes and mangetout in the dressing. Crumble over the feta and serve the veg with the lamb chops.