Heat 1 tablespoon butter and 1 tablespoon oil in a large nonstick skillet over low-medium heat, add scallion greens and sauté for a couple of minutes, until softened. Add bell pepper, if using, and sauté for a couple of minutes until softened.

Add the additional 1 tablespoon of oil, turn the heat to medium and add potatoes, roast beef and season well with salt and pepper and a few shakes of paprika. Let the mixture sit for a few minutes to get crusty on the bottom, then turn the hash over in large-ish pieces to continue to heat through. Do whatever you need to do to heat everything well, create crusty bits, and retain some soft, tender aspects to the potatoes while not overcooking the meat. This is easier than it sounds - I am just pointing out your hash goals. Taste and season as desired. Serve immediately with eggs, if you like.