Heat a large cast iron skillet over medium heat. Add the oil. When the oil is hot, add the onions to the skillet and cook until they become translucent.
While the onions are cooking, warm the sub rolls in the oven at 250°F.
Increase the heat to high and add the steak to the skillet.
Cook the steak until it is browned but still slightly pink in the center, or medium-rare. Season the steak and onions with salt and pepper.
If using green peppers and mushrooms, add them to the steak and onions to warm through before doing the next step.
Place the pieces of cheese over the hot steak in the pan, placing them so two pieces are together over one quarter of the steak and onions. Allow the cheese to melt, then scoop each quarter into a warm, split sub roll.
Notes
*You can also make our keto dinner roll recipe and shape it into 4 rolls, instead of six. Bake for an additional 10-15 minutes.**Freeze the steaks for 30 minutes and slice with a sharp knife to make it easier to slice thin or ask the butcher to slice them for you.Our recipes may contain links to affiliate websites, and Keto Chow receives an affiliate commission for any purchases made by you on the affiliate website using such links. To see the full recipe on Cronometer, you can add Keto Chow as a friend in the “Sharing” tab if you have a Gold Cronometer Membership. Our email is hello@ketochow.net.