Make the marinade. In a bowl, add the slices of tender cut beef. Grate 1/2 of the pear, ginger, and garlic into the same bowl. Add soy sauce, apple cider vinegar, oyster sauce, Gochujang chili paste, cornstarch, and brown sugar. Toss to coat well. Marinate the beef for 45 minutes.
For the veggies: slice 1/2 of the pear, squeeze lime to avoid browning. Shred the green or savoy cabbage, purple cabbage, daikon, and carrot. Slice the cucumber and scallions. Set aside.
For the sauce. In a bowl, add grated ginger and garlic. Add Gochujang, mayonnaise, mustard, sugar, and season with salt. Stir to combine.
Heat a cast-iron pan or grill pan with oil. Add the beef slices in batches, do not crowd the pan. Cook the beef for 1 minute on each side or until golden brown.
Time to plate the salad. On a serving platter, place your veggies, beef, and sauce. You can serve it hot or cold. Enjoy!