In a large skillet, heat oil over medium-high heat. Add garlic, ginger and scallions, and stir for about 2 minutes, or until vegetables soften.Add carrots, celery and red pepper and continue cooking for another 2 to 3 minutes.
Add cabbage and tofu, stirring occasionally to prevent vegetables and tofu from sticking.
In a small bowl, whisk together soy sauce, rice vinegar, honey or agave and sesame oil until blended. Pour over vegetables and tofu and stir gently.
Add shirataki and toss. Cook for another few minutes, until the sauce is mostly absorbed and the stir-fry is heated through.