In a large skillet, heat olive oil over medium high heat and brown beef until fully cooked. Drain excess fat. Add garlic, onion and mushrooms to skillet. Return to heat and cook until onion is translucent and mushrooms are soft.
Add A.1., soy sauce, vinegar, ginger and Sriracha. Stir until well combined and cook just until warmed through and ready to serve.
To serve, spoon mixture into a lettuce leaf and wrap to pick up and enjoy like a taco. If desired, pair with a splash of soy sauce mixed with freshly grated ginger for dipping.