Take the steak out of the fridge and let it warm up a little as you get started with the onion.
Put a skillet on at medium heat with a couple of tablespoons of olive oil – just eyeball it. Cut up the onions into the strips that are the width that YOU want them to be. I like about 3/8″.
Put the onion strips into the skillet,sprinkle with a little salt and pepper. Toss and turn them as they start to get translucent.