To prepare the chaffle, whip the egg white until frothy. Add the sour cream and almond flour and blend well. Mix in the cheese.
Preheat the mini waffle maker as per manufacturer's directions. When hot, add half the batter and cook for 7-10 minutes or until the chaffle is golden brown and releases easily. Repeat with the remaining batter.
Meanwhile, warm the beef broth in a small skillet or pot. Add the sliced beef to heat through - but don't over cook it!
To assemble, place the drained beef on the chaffle, top with cheese (optional) and serve with the remaining broth on the side.
Notes
Recipe Card Tips
Skip the au jus packet and use low-sodium beef broth instead. It does the same job without the hidden sodium and carbs.
Warm the beef just until heated through in the broth. Overcooking toughens it up fast.
Make the chaffles ahead if you like, then reheat in the toaster or waffle maker before assembling.