Prepare ½ c rice according to package directions. Then thinly slice ½ lb skirt steak, ⅛ c chopped onion, 1 chop chopped broccoli, and thaw ⅓ c frozen edamame if not prepared already.
Heat up a cast iron skillet over medium-low heat, then add 1 T neutral oil. Once pan is hot, cook ⅛ c chopped onions and 1 clove garlic, chopped over medium-low heat. It'll take about 5 minutes, and onions will be translucent and soft when they're ready.
Once onions are softened and turning translucent, add ½ lb sliced skirt steak. Cook for about 3 minutes on the first side, then flip each slice to cook for 3 minutes on the other side. This will give you medium-rare beef slices.
While beef is cooking, prepare sauce. Pour ¼ c beef stock and ¼ c soy sauce into a small mixing bowl, then add ½ teaspoon dark brown sugar. Whisk until incorporated.
After the beef has started cooking, add sauce and veggies. Stir every few minutes and cook for about 7-10 minutes or until veggies are tender and sauce has thickened.
Once sauce is almost as thick as you'd like it, take pan off the stove and dish up. The sauce goes from too think to too thick quickly, so remove right before you think it's thick enough.
Serve over brown rice.