Directions: Bring water to a boil in a large pot. Have ready a large bowl of ice water. Blanch spinach for 1 minute in the boiling water, then quickly remove it and plunge it into the bowl of ice water. This quick process preserves the bright green of the spinach and keeps it from overcooking. Drain the spinach well, then squeeze out as much moisture as possible. Transfer the spinach to a cutting board and coarsely chop it. Heat oil in a large skillet. Add the macadamia nuts. Saute the nuts until they just begin to brown, about 1 minute. Add the ginger and garlic. Saute about 30 seconds longer. Do not allow the garlic to brown. Add the spinach and soy sauce, and saute 2-3 minutes longer, until the spinach is heated through. Remove from heat, splash with rice vinegar, and serve immediately. Alternative: Brown the nuts in a dry pan and remove. Heat 1 or 2 teaspoons of canola oil and warm the ginger and garlic. Continue as directed in the original version.