Heat 1 tablespoon of the oil in a large skillet over medium high heat. Add the shrimp and cook 60-90 seconds on each side, until pink and cooked through. Add the garlic and toss for another 15-30 seconds. Remove the garlic to a plate and set aside.
In the same skillet, heat the remaining oil. Add the mushrooms and cook until they start to brown, 2 to 3 minutes. Add the carrot and green onions and cook another 2 minutes. Add in the cabbage and cook an additional 2 minutes.
Combine the soy sauce, water, cornstarch, and sriracha in a small bowl and whisk. Pour the mixture into the vegetables and stir. Add the reserved shrimp and remove from the heat.
If desired, char the tortillas over a gas stove or in a dry skillet. Serve the shrimp mixture in the tortillas, topped with hoisin sauce and fresh cilantro.
