In a large bowl, combine the sliced sirloin, onion, garlic, soy sauce, gochujang, rice vinegar, coconut sugar, and red pepper flakes. Toss until every piece of beef is coated. (Optional: cover and refrigerate up to a day ahead.)
1 lb sirloin steak, 1 small onion, 3 garlic cloves, 3 Tbsp soy sauce, 2 Tbsp gochujang, 2 Tbsp rice vinegar, 2 Tbsp coconut sugar, 1 tsp red pepper flakes
Heat the sesame oil in a large skillet over medium heat. Once shimmering, add the beef along with all of the sauce. Cook for 7 - 12 minutes, stirring every couple of minutes, until the beef is cooked through and the sauce has reduced to a glossy glaze that clings to the meat.
1 Tbsp sesame oil
Meanwhile, microwave the edamame according to the package, then toss it in a small bowl with the cucumber, soy sauce, sesame oil, and rice vinegar. Heat the rice.
1 cucumber, 1 cup frozen shelled edamame, 1 Tbsp soy sauce, 1 tsp sesame oil, 1 tsp rice vinegar, 4 cups cooked white rice
Divide the rice between four bowls. Top with the beef and cucumber edamame salad, sprinkle with sesame seeds, and serve.
Sesame seeds