Slice the flank steak into strips, then place them into a ziplock bag.
In a bowl, combine the sesame oil, garlic, soy sauce, shallots, ginger, brown sugar, and Sriracha sauce. Then pour the bowl’s contents into the ziplock bag with the steak, seal it.
Make sure you push the air out of the ziplock bag and rub it to disperse the marinade evenly. Chill the bag and its contents for 2 to 4 hours. Tip: If you’re using bamboo skewers, soak them in water as you marinate the steak.
Skewer the strips of beef, then grill them at 600 degrees Fahrenheit or 320 degrees Celsius for about 2 minutes on each side.
Serve the grilled beef satay in peanut sauce. Enjoy!