In a small bowl, combine the coconut aminos, fish sauce, sesame oil, rice vinegar, ginger powder and arrowroot. Whisk until well combined and set aside.
Heat a large nonstick skillet over medium high heat with avocado oil. When the oil is hot, add the shallot and garlic. Cook, stirring, until the shallots are just tender, about 2 minutes.
Add the mushrooms, salt, fresno chile and water chestnuts. Cook, stirring occasionally, until the mushrooms are tender, 3 to 4 minutes.
Pour in the sauce and stir to combine. Allow the sauce to thicken, which should only take about 1 minute.
Remove from heat and stir in the cilantro.
Serve in lettuce cups and enjoy!