For frying in a fry pan, you need enough oil for the food to be approximately half submerged. Keep in mind that, as you add food, the oil level rises. So if the food is 1" thick you don't have to start with 1/2" of oil.
When you think the oil is ready, drop a small bit of bread crumbs into the oil. It should start bubbling right away. If it does, you can start adding the tenders.
Don't crowd the pan. When the bottom is the right color, turn them over. When the second side is the right color, take them out. With tenders, this shouldn't take more than a minute or two on each side. They should be done at that point. Cut one open to be sure.
"If you want to make an apple pie from scratch, you must first create the universe." -Carl Sagan