Most tandoori chickens look and taste the same: bright red and charred. Tikka, too, teases the taste buds similarly just about wherever it is served. Korma, biryani, vegetable samosas we know them well. Tipu Rahman and his wife, Bithi Begum, both from Bangladesh, put out respectable renditions of all of the above for lunch and dinner at their handsome 45-seater (with just as many seats on an outdoor patio), but the less conventional dishes are what distinguish this North Miami Beach spot from other vindaloo venues. You won't, for instance, find the Bangladeshi appetizer of fried grouper fritters (mas bhora) on every menu, nor karahi specialties in which meat, poultry, or fish gets quick-cooked in a woklike skillet heated by coals. Heelsha's lamb karahi is one fired-up stir-fry: succulent pieces of meat melded with tomato, onion, green pepper, and garlic, then kicked up with cumin, coriander, and cardamom. It is worth a trip here just for the restaurant's namesake fish, a sweet, freshwater, silver-skin shad flown in frozen from India, and roasted with all manner of aromatic spices. Prices, however, are more typical of other Indian restaurants meaning entrées are under $15 to $25.