Make sure oil is hot and on medium heat so the food is cooked properly. Always leave on kitchen paper to absorb excess oil. When taking out of the karahi make sure to drain oil off too by lightly shaking the spoon thingy!
Make sure your food is thawed out well and good (if you're using frozen rolls etc) - so that the oil doesn't lose heat when you begin frying. Main thing is to keep the oil at the proper temperature...things tend to get oily when you drop them in cold oil, they just there and absorb when that happens.
another trick is to put newspapers under towel paper that absorbs more oil. Yes definitely make sure the oil is hot enough and then turn the flame to medium. Don't put too many things to fry at once or that brings the temp down. If possible do invest in deep fryer.