Heat oven to 200C/180C fan/ gas 6. Mix 4 tbsp oil with the garam masala and some seasoning. Toss with the chickpeas in a large roasting tin, then cook for 15 mins until starting to crisp. Tip in the mixed grains, peas and lemon zest. Mix well, then return to the oven for about 10 mins until warmed through.
Transfer to a large bowl or platter, then toss through the herbs, radishes, cucumber, remaining oil and lemon juice. Season to taste and scatter over the pomegranate seeds. Any leftovers will be good for lunch the next day.