Combine the cilantro, brown sugar, honey, soy sauce, fish sauce, garlic, peppers, ginger and the lemongrass in a blender or food processor. Puree until a smooth, thick sauce forms.
Put the pork ribs in a large resealable plastic bag or shallow plastic storage container and pour the marinade over the meat, making sure it is entirely coasted. Add the lime slices to the bag and refrigerate for 1 to 4 hours.
Combine 1/2 cup water, the sugar and ginger paste in a small pot. Bring to a simmer, stirring to dissolve the sugar. Pour the syrup into a small bowl and let cool, then stir in the vinegar, cilantro, Sriracha, fish sauce, and lime juice.
Preheat oven to 250°F.
Place ribs on a large baking sheet lined with foil. Reserve the marinade. Cover tightly with foil and place on the middle rack of the oven. Let roast for 2 1/2 hours.
Preheat grill to medium.
Take the ribs out of the oven and place them on the grill. Cook for 20 minutes, turning and basting with the reserved marinade. Remove from grill and rest for 10 minutes.
Drizzle with some of the sauce and serve with the remaining sauce on the side.