Place a large skillet over medium heat and heat butter. You can also use bacon fat. Add diced onion and diced green pepper to the skillet and cook the vegetables until the onions turn translucent.
Add cubed russet potatoes and cook for 15 minutes. Make sure to cook the ingredients by stirring them occasionally.
Once the potatoes are cooked, add the leftover chopped turkey, garlic, herbs, salt, and black pepper. Continue to cook the mixture for 5 minutes or until potatoes start to char.
Check the dish for seasoning and serve with leftover gravy.