Set a large skillet over medium high heat. Add in about 1 tablespoon of the olive oil. When hot, add in as many short ribs as will comfortably fit in the pan. Sprinkle with a little salt and pepper. Brown both sides of the short ribs (about 2 minutes per side). Remove from the pan to a plate and repeat with the remaining olive oil and short ribs (only use the additional oil if needed, you may not need to add any to the pan).
In a 6-quart crockpot, add the Sans J gluten free soy sauce, brown sugar, vinegar, garlic, ginger and red pepper flakes. Whisk until well combined, until the sugar sort of dissolves into the liquid. Add the short ribs to the pot, arranging in a single layer. Cover and cook on high for about 6 hours, until the meat is really tender and easily comes away from the bone.
Carefully transfer the short ribs to a cutting board. Skim off any fat that may be in the sauce in the pot. In a small bowl, whisk together the cornstarch and water. With the crockpot still on high, add the cornstarch mixture to the pot and whisk to combine. Cover and let cook for about 5 minutes, until the sauce thickens up just a bit. Meanwhile, if desired, shred the meat with two forks (you can serve these either on or off the bone - mine fell right off the bone so I shredded the meat and served that way).
To serve, spoon some of the coconut rice onto a serving dish. Top with the short ribs. Spoon on some of the sauce and then sprinkle with the green onions and sesame seeds.
Recipe by Make Mine Gluten Free at https://www.makemineglutenfree.com/crockpot-asian-short-ribs/