Add beef strips to a bowl with the salt, pepper and onion salt and toss to coat the beef strips
Add 2 tbsp plain flour and toss to coat beef strips with the flour.
Heat 4 tbsp oil in a frying pan over medium high heat.
Add about half the beef strips and cook until browned, about 3-4 minutes. Set aside. Add extra oil as required, and repeat process until all the beef strips are cooked and set aside.
Add more oil if required then add onions to the pot and cook for about 5 minutes until onion begins to turn brown and tender.
Add mushrooms & green capsicum, then continue to cook with the onions for a further 5 minutes, while stirring regularly.
Add thyme and garlic and stir through to mix well.
Sprinkle remaining 2 tbsp flour over the onion/mushroom mixture and stir to blend through.
Add beef stock while continuing to stir and breaking any clumps that may form from the flour.
Reduce heat to medium to low and simmer for 10 minutes to allow flavours to blend.
Remove from heat and add beef strips into pot and stir through . Season with salt and pepper as required.
Spoon the stew mixture into the hollowed-out sourdough bread rolls. You will likely have some liquid left over.
Top each bread roll with a slice of cheddar cheese and place on a baking tray.
Place bread bowls under a griller and grill until cheese melts. About 90 seconds
Serve with some of the hollowed-out bread to be used for dipping.