Near as I can tell, it's probably the local economics. It seems to me that the cost is different per "component" but would probably balance out in the end.
Chinese food, generally speaking, relies more on fresh vegetables (carrots, peas, bean-sprouts, broccoli etc.) and meat. This means that the storage costs and spoilage costs are higher relative to Indian food, which is higher in legumes and beans that are much easier and cheaper to store, and last forever when dry.
On the other hand, Chinese is generally quicker to prepare (think stir fry, though not only), which means less time on the fire, and less man-power used. Indian food usually requires more cooking time, which may mean that the restaurant has a larger capital outlay for stove space.
Aside from that, in my experience at least, Indian is usually a register above Chinese for "comparable" places. The Indian equivalent of a Chinese place serving simple rice and 10-12 stir-fry dishes would be a simple Thali bar, but there aren't many of those, as us Westerners like to order several different meat/vegetable main dishes at a time, as opposed to a set menu.
Anyway, note that I haven't done any proper costing of these type of food preparation.
The cut is important for both techniques. For sauteing, you need a lean cut - fillet, sirloin, or good rump steak. These should be cooked quickly over a high heat. As Cerberus has suggested, if you are cooking something else in the same pan, take the beef out and re-add it later; don't boil it in a sauce.
Stewing beef needs some fat and cartilage which breaks down during slow cooking and tenderises the meat. Packs of such beef are usually sold as such in the supermarket; look for a pack with plenty of fat marbled through the meat; 'Lean stewing steak' is as useful as a waterproof teabag! My personal favourite stewing beef is brisket, as it breaks down into nice tender fibres after 2-3 hours cooking.
Contrary to popular belief, browning meat does nothing to 'seal in the juices'. It simply provides a bit of extra colour and flavour by 'caramelising' the outside a little. So if you have a strong flavoured stew (like a chilli, for example), just throw the chunks of meat straight into the sauce.
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It is a combination of the marinade (with yoghurt and lemon juice probably being the main factors in the tenderness) and the hot, fast cooking in the tandoor, further enhanced by the use of metal skewers which conduct the heat to the middle of the meat quickly. A good tandoor chef will time the cooking perfectly so that the meat is safely cooked but hasn't dried out.