Two options have now come up, one of which was already there, but I discovered it last year only. The food court in Inox recently opened after almost a 2-year delay. A large hall with a vast seating area is interspersed with several stalls serving a wide variety of cuisine like Tandoori, Lebanese, Chinese, Indian, etc. Food is nice and is served hot. You buy a food card (plastic card like a debit/ATM/credit card), minimum Rs 200 (out of which Rs 25 is deposit value), against which you are allowed to buy food worth Rs 175. Then, you carefully pass by each and every food stall, select your item, get your card swiped on that counter, order and then take your dish and sit in the hall and enjoy your meal. And if you have spent less than Rs 200, you will get your entire balance back. It's just that when you buy the card, the minimum value of the card has to be Rs 200. They have recently started a dessert counter too, much to my liking (strawberry cheesecake is nice, so is chocolate mousse) but they do not accept the food-card here. You have to buy your desserts only against cash. But your card can buy Gellato ice-creams.
The other options is The Gourmet Shoppe in the Oberoi Hotel, the shorter of the two towers. The entrance is from the back-side, opposite Bakhtawar building. Great food, slightly expensive but totally worth it, and a decent seating arrangement. I relish their chicken biryani (in the range of Rs 160/- odd, give or take a few rupees) and Chicken Malbari roll (Rs 125/-) Take-aways are allowed. I absolutely love this place.
But clearly we need some more non-vej options at Nariman Point.