Chop the bacon into small pieces. Heat a large nonstick skillet (I use a 12-inch skillet) over medium-high heat and cook the bacon until crispy and much of the fat has rendered. Leaving the fat drippings in the skillet, transfer the cooked bacon to the bottom of your slow cooker.
Transfer the chopped onion to the skillet with the bacon fat over medium heat and sauté for 3-5 minutes, until the onion has softened. Add the mushrooms and continue cooking, stirring occasionally, until the mushrooms have shrunk in size and turn a deeper brown, about 5 to 8 minutes. Stir in the garlic and sauté for another 1-2 minutes, until the garlic is fragrant.
While the onion and mushrooms are sauteing, you can prepare the rest of the recipe by chopping the potatoes, bell pepper, and meat.
Transfer the chopped potatoes, bell pepper, and meat to the crock pot, in addition to the sauteed mushroom and onion mixture. Pour in the beef broth, Worcestershire sauce, dried oregano, sea salt and give everything a big stir.
Secure the lid on the crock pot and cook for 4 hours on High Heat or 7-8 hours on Low Heat.
Once the soup has finished cooking, taste it for flavor and add more sea salt and black pepper to taste.
Serve steak and potato soup in big bowls garnished with chopped green onions and with crusty bread or cornbread. You can top the soup with cheddar cheese and/or sour cream for a delicious creamy effect.