Prepare Sauce: Combine Bulgogi Sauce ingredients in a mason jar. Tightly close lid and shake to combine. Feel free to make a double batch if you want extra sauce to pour over the rice.
Prepare Sushi Rice: if you haven't already make sure you are preparing your sushi rice.
Marinate Steak: Very thinly slice ribeye steak into strips. Place in a bowl or reuseable silicone bag. Pour approx. 1/3 of the Bulgogi Sauce over the meat; toss to coat. Let marinate 15-30 minutes.
Cook Steak: Bring a large cast iron skillet to medium-high heat. Add butter and let melt; swirl to coat the pan. In batches, add marinated strips of beef and sear on both sides (approx. 30-60 seconds per side). Transfer to a plate and repeat until all the meat is seared.
Extra Sauce + Toppings: Return all the meat to the pan and add the remaining sauce, sliced green onions and some sesame seeds.
Build Bowls: Divide rice, beef bulgogi, kimchi, cucumbers and green onions between 4 bowls. Garnish with sesame seeds and extra sauce. Enjoy!
Notes
Crushed Pear: a lot of bulgogi recipes call for crushed pear, I didn't include that in this version in an effort to simply things, but feel free to add a little if you prefer. This is my spin on this classic dish so some ingredients may differ!
Extra Sauce: feel free to double the sauce so you have extra to pour over your rice!
Cut of Meat: I tested this with sirloin steak and ribeye - the ribeye is significantly better (no surprise there), so that is what I recommend. You could make ground beef work too if you prefer!