Place the boneless rib eye steak in the freezer for about 30 minutes to firm it up slightly, making it easier to slice.

Slice the beef thinly against the grain into ¼-inch thick pieces.

In a medium bowl, combine the grated pear, reduced sodium soy sauce, brown sugar, toasted sesame oil, minced garlic, freshly grated ginger, and gochujang. Whisk until well blended and the sugar has dissolved.

Place the sliced beef into a gallon-size Ziploc bag, pour the marinade over it, seal tightly, and refrigerate for at least 2 hours, preferably overnight.

Heat 1 tablespoon of vegetable oil in a large cast iron grill pan over medium-high heat.

Add a portion of the marinated beef to the hot pan in a single layer. Sear for 2-3 minutes on each side until golden brown.

Remove the cooked beef and repeat with the remaining oil and marinated beef.

Transfer the cooked beef to a serving platter, garnish with sliced green onions and toasted sesame seeds, and serve immediately.