Several things here. First of all, as long as you aren't trying to deep-fry, you most certainly can cook Indian food with olive oil. It is not traditional, sure, but I know quite a few Indians who do it from time to time, including my mother-in-law.
It is true that I also know some Indians who would never do it (in fact, a Keralan friend's mother who was cooking with us at my house once to demonstrate some recipes was shocked at the lack of coconut oil and refused to consider either canola or olive and instead went with mustard).
It may affect the taste slightly, but if you don't use much, it isn't going to be a dominant flavor. (If you're not sure about it, start small - mix half and half with your regular oil and see if it works for you, then gradually increase the olive oil in the mix.) If you can cook avial with mustard oil, you can cook palak paneer with olive oil. :-)
But yes, you can either heat the olive oil or mix it with something (or both) and mellow it. Mixing with an acid like lemon juice or a good vinegar works well, and/or crushing garlic or herbs in it to make a paste or a dressing. You can cook it or just leave it as is.
A Greek girl who lived with us for a year when I was in high school used to put the olive oil in a frying pan then toast a slice of bread in it, then top it with a sprinkling of sugar. The combination of the heat and the sugar mellows the flavor a bit. (In this case, it was heated long enough to make the bread golden when you put it in, and heated enough before not to simply soak the oil up when the bread goes in.)
It will still taste like olive oil, though. It just won't be quite as dominant and "green" tasting.
EDIT:
As for references for the propriety of cooking onions in olive oil over a moderate heat, looking in Tess Mallos's The Complete Mediterranean Cookbook, pretty much every recipe which starts with the ingredients "2 Tbsp olive oil, 1 large onion" also starts with the instructions, "Heat oil in a pan. Gently cook the onion in the oil until translucent, about 10 minutes." (Here's one of them someone has put online.)
And here is a chart of smoke points of oils, and here is another. You will perhaps note that the smoke point of coconut oil is listed as 350, and one of these links lists the smoke point of extra virgin olive oil as a range between 325-375. If you accept that it is possible to cook onions for Indian food in coconut oil without the oil smoking, which much of southern India would agree with, then it must be possible to cook onions for Indian food in other oils with a similar smoke point.
This method of cooking onions in olive oil will not take the oil to a smoking point. If you reach a smoking point, you should reduce the heat and start again with fresh ingredients, but it is absolutely eminently possible to avoid reaching that point. This method of cooking onions in olive oil is very easily transferable to Indian recipes. Again, it is not traditional to use olive oil in Indian cooking, but it is perfectly possible for most dishes. In my cooking, the only Indian dishes cooked on the stove top that are too hot for this are deep-fried dishes. If you are doing Indian-Chinese and cooking stir-fry then yes, the other link may apply if you are using the stir-fry method.
However, taking that one step further, it is also actually possible to adapt the same recipes normally made as stir-fries to be cooked in a regular frying pan and at lower heat. It is, again, not traditional, and it is an adaptation. But if you prefer to use olive oil you can make other changes to make a dish that is very similar to the original dish, while not being identical.
