Heat a large skillet over medium-high heat for about 2 minutes. Add the ground beef, breaking it apart with a wooden spoon. Cook for 5-7 minutes, or until the beef is browned and no longer pink. If there's excess fat, drain it carefully, leaving a small amount for flavor.

Reduce the heat to medium and stir in the soy sauce, sesame oil, gochujang, minced garlic, grated ginger, erythritol, and rice vinegar. Cook for another 3-5 minutes, stirring occasionally, until the sauce thickens slightly and coats the beef.

While the beef cooks, slice the cucumbers thinly and chop the green onions. In a separate bowl, combine the cucumbers, green onions, and sesame seeds. Toss gently to mix everything.

To serve, layer the spicy beef over a bed of cucumber salad in individual bowls. Garnish with extra sesame seeds and green onion slices on top.