Prepare the short ribs: Sprinkle ribs on all sides with salt and pepper; cover and chill 12 to 24 hours.
Let ribs stand at room temperature 30 minutes.
Preheat oven to 300°F. Whisk together broth, brown sugar, soy sauce, vinegar, and Sriracha in a medium saucepan. Bring broth mixture to a boil over high. Reduce heat to medium, and simmer, stirring occasionally, until reduced to 2 cups, 12 to 15 minutes.
Heat 2 tablespoons of the oil in a large Dutch oven over medium-high. Place half of the ribs in hot oil, and cook until browned on all sides, about 3 minutes per side. Repeat with remaining oil and ribs. Transfer ribs to a plate, and discard drippings.
Pour broth mixture in Dutch oven, and bring to a boil over medium-high. Place ribs in Dutch oven. Add onion, garlic, and ginger, nestling them around ribs; add bay leaf and parsley and cilantro sprigs. Place a piece of parchment paper directly on ribs and herbs, and cover Dutch oven with a tight-fitting lid.
Roast in preheated oven until meat is tender and pulls away from bone, about 2 hours and 30 minutes to 3 hours. Remove from oven, and let stand, covered with parchment and lid, 30 minutes.
Remove lid and parchment paper. Transfer ribs to a serving platter, gently remove bones, and discard; cover with aluminum foil to keep warm. Skim fat from cooking liquid in Dutch oven, and pour liquid through a fine wire-mesh strainer into a large bowl; discard solids. Reserve cooking liquid for gravy.
Prepare the gravy: Heat butter in a medium saucepan over medium. Add onions, and cook, stirring occasionally, until tender and golden brown, about 10 minutes. Sprinkle flour over onions, and cook, stirring constantly, until flour is golden brown, about 2 minutes.
Gradually whisk in reserved cooking liquid. Cook, stirring often, just until mixture comes to a boil and is smooth and thick, about 5 minutes. (If mixture is too thick, add up to 1 cup remaining reserved cooking liquid, 1/4 cup at a time, until mixture reaches desired consistency.) Season with salt and pepper. Serve with short ribs and Coconut Rice. If desired, top with a fried egg.