Janchi Sanjeok

1. Prepare the beef sirloin by slicing it into thin strips, approximately 5cm long and 1cm wide.

2. In a bowl, combine the sliced beef sirloin with 10g of minced garlic, 20g of soy sauce, 5g of sesame oil, 5g of sugar, and 1g of black pepper. Mix well and let it marinate for at least 20 minutes.

3. Slice the shiitake mushrooms, red bell pepper, yellow bell pepper, and onion into pieces roughly the same size as the beef sirloin strips.