In a large, deep skillet, heat the canola oil until shimmering. Add the onions, celery, sambal oelek, garlic, ginger and a generous pinch each of salt and pepper and cook over moderate heat, stirring occasionally, until the vegetables are softened, about 8 minutes. Add the ground chicken and pork and cook, stirring occasionally to break up the meat, until no pink remains, about 5 minutes. Stir in the hoisin, tomatoes and lime juice and bring to a boil. Simmer over moderately low heat, stirring occasionally, until thickened, about 20 minutes. Season with salt and pepper.
Spoon about 1/4 cup of the sloppy joe filling on the bottom half of each roll. Top with shredded lettuce and pickles and serve.