Prepare the Asian pickled cucumbers by placing the sliced cucumbers in a small bowl. Add the rice vinegar, sugar and salt and mix well. Cover the bowl and place in the refrigerator to pickle for 12 to 24 hours. Drain the liquid before serving.
To prepare the beef, add the onion to the bottom of the slow cooker. Make the sauce by combining the soy sauce, beef broth, garlic, brown sugar, sriracha sauce and 1 tablespoon of the sesame oil in a small bowl. Set aside. In a large skillet, heat the remaining tablespoon of sesame over medium heat. Once the oil is hot, carefully add the beef to the skillet and sear on each side for 2 minutes. Place the beef on top of the onions in the slow cooker and pour the sauce over the beef. Cover the slow cooker and cook on high for 4 to 5 hours or on low for 8 hours. Before serving, shred the beef using two forks.
For the tacos, place about ⅓ cup of beef on each tortilla and top with pickled cucumbers, carrots, cilantro and sesame seeds, as desired.
Recipe by Karman Meyer, RDN, LDN