fried onion (preferably Thai) or Durkee dehydrated onions, for serving
In a large skillet, heat the grapeseed oil until shimmering. Add the garlic and cook over high heat, stirring, for 30 seconds. Add the spinach all at once and toss until nearly wilted. Add the coconut milk and fish sauce and cook until the spinach is tender and the coconut milk has reduced, about 3 minutes. Top with fried onions and serve.