Mix together the onion, herbs, garlic, lemon rind and juice and olive oil. Season with salt and pepper and pour over the monkfish. Cover and chill for 1 hour or until required.
To make the mint raita, mix together the yogurt, mint and cayenne pepper. Cover and chill until required.
When ready to serve, remove the monkfish from the marinade and thread on to skewers. Place the fish under a preheated hot grill and cook for about 10 minutes, turning occasionally, until browned and cooked right through.
Serve the monkfish kebabs with a bulgar wheat salad and the mint raita.