Suppose I have a lot of pre cooked schnitzels that I want to fry in the pan. I begin by frying in batches, after adding the first batch, in sometime, all the pieces are cooked, however when I remove the cooked pieces and add the new batch, it seems so sometimes the new batch gets burnt because the pan temperature rises too high. Is there a better way to fix this than simply turning the stove off for sometime?
This is about regulating the heat of your pan. You could use an infrared thermometer to help, then you can develop a feel for what is happening when you add food to your pan. Adding food to a hot pan will drop the temperature quite a bit. I often turn the burner up a bit when I add food, then dial it back as it cooks, and the temperature will come back up. There are some variables at play, such as how much you are crowding the pan, the temperature of the food when you put it in the pan, how long you are cooking it, and the time between batches.
When cooking something that is coated or breaded, you have the added issue of loose bits remaining in the pan. These overcook and burn, and often stick to the next batch. Maybe that is at least part of what is happening here. I would suggest is using a skimmer to remove any bits that fall off the first batch, before you add the next batch.
You shouldn't have turned it so hot in the first place.
The point of regulating the temperature is to preheat your pan+oil at the correct setting until it's at roughly the rough temperature, then add the first batch, and then leave it at that setting throughout the batches. The oil temperature will fall off somewhat when you add the new food (hopefully not too much - it's good to rest schnitzels at room temperature before frying them) and then go up again, but roughly, once you've gotten a feel for which setting is right for your combination of pan+stove, you'll stay with it from beginning to end.
What you're doing is selecting a setting which is too hot. You're not waiting for the pan to come to equilibrium, but adding the first batch while it's still heating up. This works more-or-less for the first batch, but since the pan continues to heat up afterwards, the later batches are at too high a temperature. You're then trying to correct for this by turning off the stove, then you have to turn it on again... basically you're manually doing the work of the temperature controller inside the stove, but way too coarsely, and with too large a delay.
The situation I described in my first paragraph is the optimal one. You can sometimes get away with the fast-and-overly-hot preheating when you have only one or two batches of food, because then the pan has not yet overheated when you turn it off. But you have to be quite adept at doing it, and the results aren't as good as when you have a properly, slowly preheated pan. And sometimes, when you have very many batches (e.g. with making crêpe after crêpe) with a heavy iron pan, it's almost impossible to avoid a slow creep up of temperature, and then you have to dial the stove down a mark after it becomes too hot. This is a much subtler regulation though, happening much later and in much smaller increments than what you describe.