Combine oxtails, onions, green onions, thyme, browning sauce, red pepper flakes, seasoning blend, salt, hot sauce, garlic, and bay leaves in a large pot. Let marinate in the refrigerator, stirring as often as you can, 8 hours to overnight. Place pot over medium heat. Pour in enough water to cover the oxtails. Simmer for 2 hours. Add beef broth and cook until oxtails are tender, about 2 hours 45 minutes. Add lima beans and cook until heated through, about 15 minutes. Discard thyme and bay leaves.