Prepare ingredients: Slice beef sirloin thinly (if not pre-sliced). Drain and rinse shirataki noodles thoroughly, then pat dry and cut into shorter lengths if desired. Cut napa cabbage into bite-sized pieces. Slice shiitake mushrooms. Chop green onions for garnish.

In a large pot or electric hot pot, combine dashi, soy sauce, sugar-free mirin, and erythritol to create the sukiyaki broth. Bring to a gentle simmer over medium heat.

Add napa cabbage and shiitake mushrooms to the simmering broth. Cook for 5-7 minutes until vegetables are tender-crisp.

Add shirataki noodles and thinly sliced beef to the pot. Cook for 3-5 minutes, ensuring beef is cooked through. Do not overcrowd the pot; cook in batches if necessary.

Crack eggs into individual small bowls (one per person) for dipping, if desired. Alternatively, gently crack eggs directly into the simmering broth and poach until whites are set and yolks are still runny, about 2-3 minutes.