First of all, place a cast-iron skillet over medium heat. After a few minutes, add oil and onions in the skillet. Then, put bell peppers in it and keep stirring until the mixture becomes caramelised. It will take around six minutes. Now, add salt, pepper and garlic and stir the mixture again for about half a minute.
Make sure that all the ingredients are mixed well in the skillet. It is extremely important for you to keep stirring the ingredients while they are on the stove, otherwise, you will not be able to get the best results.
Now take a saucepan and put it on medium heat before adding the meat to it. Add a little oil to the pan now and stir the meat around using two metal spatulas. You have to cook the meat for around two minutes and then add the sautéed vegetables in the pan. Now, add the cheese slices in the pan and allow them to melt.
After the cheese melts, take out the cheesed meat with the help of a spoon and put it on the warm buns. You can pour your favourite sauces on the buns as well. Mostly, people use mayonnaise in the sandwiches. However, you should keep in mind that it will make your sandwich quite heavy. You can also put a cheese slice on the meat after putting it on the buns instead of adding the cheese in the pan. Cover the sandwich and have it along with your favorite drink.