It's best not to use any oil or other cooking fat in cooking. Extra Virgin Olive Oil (EVOO) can be used in baking below 180 deg C. If you want to stir fry then you can use water to soften vegetables, or I think some people use a little EVOO mixed with oil, or maybe a spray of this combination say 50:50. For tomato based sauces I often use passata to soften onions and garlic then add other vegetables. You can drizzle EVOO at room temperature onto cooked foods. Some of us are now used cold-pressed extra-virgin rapeseed oil in the UK where provenance is known, as it's grown here, in the same way as EVOO.