In a large saute pan, or wok, add oil over high heat. Add in garlic and ginger, cook for 10 to 15 seconds. Add sirloin and saute, stirring frequently until just cooked through, approximately 1 minute. Stir in carrots, celery, red bell peppers and red onions sauteing briefly, 1 minute. Add in sake to deglaze, then add in soy, hoisin and cornstarch slurry. Continue to stir on high heat for about 30 seconds. Stir in bean sprouts and sesame oil to combine and remove from heat.
Steam or heat rolls in a warm 250 degree F oven, tightly wrapped in foil for 8 minutes.
Take rolls, 2 at a time, and leaving them attached, gently split open and fill with approximately 3/4 cup of stir-fry mixture. Garnish with green onions and serve immediately.