In a large skillet, heat the vegetable oil over medium-high heat. Add the ground beef and cook until browned, breaking it apart with a spatula, about 5-7 minutes. Drain excess fat if necessary.

Stir in the minced garlic and ginger, cooking for an additional 1-2 minutes until fragrant.

Add the soy sauce, brown sugar, sesame oil, and red pepper flakes to the skillet. Stir well to combine and let simmer for 3-4 minutes until slightly thickened.

While the beef is simmering, warm the corn tortillas in a separate skillet over medium heat for about 30 seconds on each side until pliable.

To assemble the tacos, place a generous scoop of the Korean beef mixture onto each tortilla. Top with shredded cabbage, diced cucumbers, green onions, and cilantro.

Serve with lime wedges on the side for squeezing over the tacos.