Combine cumin, chili flakes, peppercorns, and salt in small bowl. Combine water and baking soda in medium bowl. Add lamb and toss to coat. Let sit for 5 minutes. Add 1 tsp sauce, Shaoxing wine, cornstarch, and salt to lamb mixture and toss to coat.
Heat 1 inch of oil in 12-inch nonstick skillet. Drain gnocchi over colander, then add to hot oil and cook, without moving, until well browned on 1 side, 2 to 3 minutes. Flip gnocchi and cook until browned on second side, 2 to 3 minutes longer. Using slotted spoon, transfer gnocchi to paper towel-lined plate.
Add lamb mixture to now-empty skillet and cook, stirring occasionally, until lamb is cooked through, 3 to 5 minutes. Stir in garlic and ginger and cook until fragrant, about 30 seconds. Stir in celery and cumin mixture and cook until celery is tender, about 2 minutes. Off heat, add gnocchi and toss to combine. Serve immediately, passing extra vinegar separately.