1. Heat oil in skillet over medium-high heat. Add mushrooms and bell pepper, and sauté 8 to 10 minutes, or until mushrooms have released their juices and begin to brown.
2. Add garlic and ginger, and sauté 30 seconds. Add soybeans, hoisin, vinegar, and sriracha, and sauté 2 to 3 minutes, or until soybeans are heated through and mixture is well combined.
3. Remove from heat, and scoop 1/4 cup soybean mixture into each lettuce leaf. Sprinkle each wrap with green onions, and serve immediately.