Heat chili flakes in canola oil. Add shrimp, salt and black pepper; cook until just opaque, 2 minutes. Remove shrimp and reserve. Add celery, snow peas, garlic cloves, and grated ginger. Cook until crisp-tender.
Stir in the shrimp, rice vinegar, and soy sauce. Cook 2 minutes more.
Serve with rice and sliced scallions.